Utils: add lower bound checks for MediaFormat keys

These checks were earlier merged as
commit 10f165c2
and then reverted due to some failures seen due to bits-per-sample
check.

This CL makes the following change:
1. removes bits-per-sample check
2. changes channel count check to <0 for mpeg h
3. retains other checks.

Test: atest CtsMediaV2TestCases

Bug: 146923138

Change-Id: I91c8d7c52b6c409b3a78b5441749246bd77acc88