Reduce ENABLE_ROLLBACK timeout to 0 for timeout test.

testEnableRollbackTimeoutFailsRollback works by setting the enable
rollback timeout to 1 millisecond so that we will always time out, but
the test is failing some times because apparently we enable rollback
within the 1 millisecond limit. Reduce the timeout to 0 milliseconds to
try and reduce test flakiness.

Before lowering the timeout, the test failure was easy to reproduce
locally. After lowering the timeout I have not once been able to
reproduce the test failure locally.

Bug: 134373106
Test: atest RollbackTest:com.android.tests.rollback.RollbackTest#testEnableRollbackTimeoutFailsRollback
Change-Id: I44f9e786d2a2285475ee423e34d06f5b5a5271e1
Merged-In: Ia25561831616dd2f2644743a399b49e35d5d4ea4