WifiServiceImpl: Fix package removal broadcast handling

This has been broken since ag/616463.
Changes in the CL:
a) Move handling of USER_REMOVED to the existing global broadcast
listener in the class.
b) Listen for ACTION_PACKAGE_FULLY_REMOVED (which indicates complete app
removal from the device) using "package" as the data scheme.

Bug: 77588735
Test: Unit tests
Test: Manually verified with logs that both user removed & package
removed broadcasts are being received correctly in WifiServiceImpl.

Change-Id: I5480a145a9255a226dbaa614c906121d274b919c
2 files changed