A problem occurred evaluating project ':flutter_downloader'.

Android issue:

```
FAILURE: Build completed with 2 failures.

1: Task failed with an exception.
-----------
* Where:
Build file 'C:\Users\Dell\AppData\Local\Pub\Cache\hosted\pub.dev\flutter_downloader-1.10.4\android\build.gradle' line: 30

* What went wrong:
A problem occurred evaluating project ':flutter_downloader'.
> No signature of method: build_eilr0qkxli952v8kt4w3yzx7i.android() is applicable for argument types: (build_eilr0qkxli952v8kt4w3yzx7i$_run_closure2) values: [build_eilr0qkxli952v8kt4w3yzx7i$_run_closure2@2b6728e3]

* 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.
==============================================================================

2: Task failed with an exception.
-----------
* Where:
Script 'C:\src\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 463

* What went wrong:
A problem occurred configuring project ':flutter_downloader'.
> Failed to notify project evaluation listener.
> Cannot invoke method substring() on null object
> compileSdkVersion is not specified. Please add it to build.gradle

* 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 17s
Exception: Gradle task assembleDebug failed with exit code 1
```