Revert "Fix android.view.inputmethod.cts.OnScreenPositionTest"

This reverts commit 1e8ededcf95b26d9f8d1c20a9eab0369e571a2b2 [1].

Reason for revert:
This workaround is no longer necessary thanks to a recent change in
the Framework side [2], which lets Instrumentation#startActivitySync()
also take Activity entering animation into account.

 [1]: I516769289aa3c442201bde736530e649fff8e9b9
 [2]: Ifd7bfd41b39518518f4013fad80c3acd1e8b2354
      feb2e1e0b46926f79904fc0fde505552276f168b

Bug: 120424805
Test: atest CtsInputMethodTestCases
Change-Id: Ie769a4dbf0ec75214e44a301a72836feb24336f1
4 files changed