Add support for combining and remove individual resource

- Fix ResourceManagerSerivce handling of adding same-type
resource in multiple calls, combine entries with the same
<type, subtype>. This is not required in existing usage,
bug could be required if we allow same type to be added
incrementally (eg. memory usage).

- Add api for removing some resources. Currently we can
add resources in multiple calls, but removeResource always
remove all resources of that client. We need this to toggle
battery stat On/Off based on actual usage of the codec.

- Add unit tests for the above.

bug: 138381810
test: ResourceManagerService_test; CTS ResourceManangerTest.

Change-Id: Icdba6c6b4c517755291668c52764169aac3071ea