Unable to Create WebViewPlugin.Jar

I made some changes, basically i just added a log as shown below

 @JavascriptInterface
    public void call(final String message) {
                 Log.d("its just a log CWebViewPlugin", cm.message());
        call("CallFromJS", message);
    }

I was unable to create jar file.
Please check the below log while im trying to execute "install.sh"

xxx-xxx:Android xxxx$ ./install.sh --debug
~/Downloads/unity-webview-master/plugins/Android ~/Downloads/unity-webview-master/plugins/Android

> Task :gradle_build:compileReleaseJavaWithJavac FAILED
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:7: error: cannot find symbol
    extends UnityPlayerActivity
            ^
  symbol: class UnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:9: error: method does not override or implement a method from a supertype
    @Override
    ^
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:11: error: cannot find symbol
        requestWindowFeature(1);
        ^
  symbol:   method requestWindowFeature(int)
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:12: error: cannot find symbol
        super.onCreate(bundle);
        ^
  symbol:   variable super
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:13: error: cannot find symbol
        getWindow().setFormat(2);
        ^
  symbol:   method getWindow()
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:14: error: cannot find symbol
        mUnityPlayer = new CUnityPlayer(this);
        ^
  symbol:   variable mUnityPlayer
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:14: error: incompatible types: CUnityPlayerActivity cannot be converted to ContextWrapper
        mUnityPlayer = new CUnityPlayer(this);
                                        ^
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:15: error: cannot find symbol
        setContentView(mUnityPlayer);
                       ^
  symbol:   variable mUnityPlayer
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java:16: error: cannot find symbol
        mUnityPlayer.requestFocus();
        ^
  symbol:   variable mUnityPlayer
  location: class CUnityPlayerActivity
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CWebViewPlugin.java:73: error: cannot find symbol
                 Log.d("Nsks CWebViewPlugin", cm.message());
                                              ^
  symbol:   variable cm
  location: class CWebViewPluginInterface
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CWebViewPlugin.java:73: error: cannot find symbol
                 Log.d("Nsks CWebViewPlugin", cm.message());
                 ^
  symbol:   variable Log
  location: class CWebViewPluginInterface
Note: /Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/src/main/java/net/gree/unitywebview/CWebViewPlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
11 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':gradle_build:compileReleaseJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
21 actionable tasks: 19 executed, 2 up-to-date
/Users/xxxx/Downloads/unity-webview-master/plugins/Android/gradle_build/build/intermediates/classes/release/net : no such file or directory
added manifest

BUILD SUCCESSFUL in 0s
1 actionable task: 1 executed
~/Downloads/unity-webview-master/plugins/Android
xxxx-xxxx:Android xxxx$ 

Please point me in the right direction.
Thank you

Start by running install.sh --debug and read the compileReleaseJavaWithJavac output. Inspect gradle_build/src/main/java/net/gree/unitywebview/CUnityPlayerActivity.java and CWebViewPlugin.java, focusing on the missing UnityPlayerActivity, mUnityPlayer, Log, and cm symbols. Done means the Android build completes without compilation errors and creates the WebViewPlugin JAR.