Use Kosmos.fakeMobileConnectionsRepository in most tests.

This CL:
- Updates Kosmos.fakeMobileConnectionsRepository to use the new
  `logcatTableLogBuffer` helper method instead of a mocked TableLogBuffer
- Updates lots of tests to use Kosmos.fakeMobileConnectionsRepository
  instead of creating a new instance of FakeMobileConnectionsRepo

Also:
 - Removes some unused values in various tests
 - Updates some TableLogBuffer mocks to use the helper method instead

Bug: 360832989
Flag: TEST_ONLY
Test: atest MobileConnectionRepositoryTest (+ others)
Change-Id: Ifd36b0d0bec5932d07276b8a8b80b504d076d7ea