AIDEGen: Replace the template files by using string in Python

Bug: 139036304
Test: 1. m aidegen;aidegen-dev Settings
      2. Confirm the modules.xml and vcs.xml under
         packages/apps/Settings/.idea/ are not changed.

Change-Id: I19c7c67823d18a04ff670f5f01d7db7e0f844888
2 files changed