Make onExecuteAppFunction non-abstract and remove timeout results.

This is required so g3 usages can stop overriding this deprecated method and the timeout logic was removed in ag/29477656


Change-Id: Icd07685ea296403b48f4c3cbd74c2e7c3ad28430
Flag: android.app.appfunctions.flags.enable_app_function_manager
Test: atest CtsAppFunctionTestCases -c
Bug: 360864791