Update media_codecs_performance_c2.xml for meet device performance

The original performance number may not able to meet from CTS since
cpu scheduling is changed in P23 for power saving. We align hevc/h264
encoder lower bound performance as P22's result to get the stable test
result for CTS.

Bug: 291689152
Test: run cts -m CtsVideoTestCases -t android.video.cts.VideoEncoderDecoderTest
Change-Id: I17a7f832c421d873a68a87eea0131d141afdc108