Change database package name align with the directory name

* Change database package name to btservice.storage to align with
  the directory name.
* Add missed annotation processor to fix Room database sometimes
  failed to generate implementation files and cause Bluetooth crash.

Bug: 123316789
Bug: 123312335
Test: Manual
Change-Id: I2b6b1ce1b67eebe289fa3c8153fd296b1ee8cf19
Merged-In: I2b6b1ce1b67eebe289fa3c8153fd296b1ee8cf19