More clean-up needed by GoogleQuickSearchBox

- Use implicit intents to communicate between app components, to
  allow them to be replaced.

- Use . prefix in manifest, to reduce the differences between
  QuickSearchBox/AndroidManifest.xml and GoogleQuickSearchBox/AndroidManifest.xml

Change-Id: Ia81e9d6354accd6cba5c66274fe0d579059d2aa8
3 files changed