[Android] Add the test cases about onActivityResult.

This patch contains the test case about onActivityResult in shared
and embedded mode.
Create a activity names "SecondActivity". In the runtime client activity,
it starts activity for result. In the second activity, it will create a new
intent, and transfer data to runtime client activity.

For embedded client test:
1. install XWalkRuntimeClientEmbeddedShell.apk
2. python build/android/test_runner.py instrumentation \
--test-apk=XWalkRuntimeClientEmbeddedTest -v -f testOnActivityResult

For shared client test:
1. install XWalkRuntimeLib.apk
2. install XWalkRuntimeClientShell.apk
3. python build/android/test_runner.py instrumentation \
--test-apk=XWalkRuntimeClientTest -v -f testOnActivityResult