[RESTRICT AUTOMERGE] SF: Disable flaky unit tests

A good number of OneShotTimer tests, and two LayerHistoryTestV2 tests
were flaky. This changes marks them as DISABLED, with a comment linking
to the bug.

Bug: 186417847
Test: libsurfaceflinger_unittest # Tests marked disabled
Change-Id: I36410b802dc03e2408ce6c4c79d975d9eb021332
Merged-In: I75a034e6a79e0469b3a321e410ca0d6db36bd5fe