Fix flaky CTS by increasing timeout bar

Increase test timeout so that the test can run on emulator/
cuttlefish. These devices doesn't have any hw accelerated codecs, and this change matches with the tests in Androidx (see reference aosp/971906)

Bug: b/407681867
Test: CtsMediaMiscTestCases android.media.misc.cts.HeifWriterTest
Flag: TEST_ONLY

Change-Id: I55c55bd9ca5d6d5e9e8b1f279e187fcb7283b287