Add tolerance to Bitmap sizes in Notification test

There can be differences in how different platforms round the maximum
Bitmap size which can lead to failures and flakiness across platforms.

Since we're testing resize from 3000px to cca. 100px, we can be tolerant
to a few pixels of difference to make the tests more stable while still
checking if code runs properly.

Bug: 332758490
Test: atest android.app.NotificationTest
Flag: TEST_ONLY
Change-Id: I920894f1af962d0d9095655b70265b8e409071cd