Drop unused test support class MockOs.

This class was introduced for use in libcore.io.DiskLruCacheTest in
commit e342455abc6b650f847d931728223411e58831ce (May 2011), but that
class was dropped in commit 4f97bfe0d9e6f4bdb43fff91f341f4722af16301
(Apr 2013), after switching to OkHttp. It now appears to be unused.

Based on the commit message at http://r.android.com/592273 ,
core-tests-support (which includes MockOs) should only use public
Android API, but MockOs imports libcore-internal classes
libcore.io.{Os,Libcore}.

Therefore, this CL drops the unused class MockOs.

Bug: 69899800
Test: Treehugger

Change-Id: I043178ecd482e1ba8bb4d068c03497191e2722eb
1 file changed