fix(android)(9_0_X): module build to download ndk with gradle tool 3.…

…5.0+ (#11620)

- After updating Android gradle tool from 3.4.x to 3.6.0, module builds no longer auto-downloads NDK if missing.
- Issue on Google's end which default to an "unstable" NDK version and tool does not support downloading unstable versions.
- Downgraded default NDK version for modules from 21.0.6113669 to 20.1.5948944
  * Avoids harmless "bad file descriptor" errors that get logged by newest NDK.

Fixes TIMOB-27798

android/templates/module/generated/build.gradle

@@ -151,6 +151,15 @@ preBuild.doFirst {
 	}
 }
 
+// If Titanium failed to set Android NDK path in "local.properties", then assume NDK is not installed.
+// Have gradle auto-download NDK by setting the version we want below. (Will fail if a different version is installed.)
+// Must be set to a stable release version listed here: https://developer.android.com/ndk/downloads
+def localProperties = new Properties()
+localProperties.load(file("${rootDir}/local.properties").newDataInputStream())
+if (localProperties.get('ndk.dir') == null) {
+	android.ndkVersion '20.1.5948944'
+}
+
 // Set up project to compile Java side before compiling the C/C++ side.
 // We must do this because our "kroll-apt" Java annotation processor generates C++ source files.
 project.afterEvaluate {