[gradle] Accessing files in build directory

[provide a description of the issue]

Environment

• Operating System: macOS Sierra
• JDK version: JDK 8
• Visual Studio Code version: 1.15
• Java extension version: 0.8.0

Steps To Reproduce

I track a build number using a text file in the build project directory, e.g., 'build.num'

First, the file can't be found using this code:

def buildNumber = new File("build.num").text.toInteger() + 1

It looks like gradle isn't being run in the same directory as the build.gradle file. So I changed the code to this:

def buildNumber = new File("${projectDir}/build.num").text.toInteger() + 1

Now the 'build.num' file is being found. The same problem exists when referencing any files from a relative location.

Current Result

File Not Found

Expected Result

Build should work the same as if running it from the build directory.

Additional Informations

首先，使用相对 build.num 路径复现 Gradle 构建，并将其与 ${projectDir}/build.num 形式进行比较。检查 VS Code Java extension 如何启动 Gradle，并验证该修复会使相对路径从构建目录解析，同时不会破坏其他构建。