C2SoftHEVCEnc: Change default dimensions and frame rate

In order to support signalling lower levels, default dimensions
and frame rate are set to smaller values, such that minimum level
calculations done with default values still stay at lowest level
supported

Bug: 151429828
Test: Uncomment the parameter for hevc level 1 in the CTS test
Test: atest android.mediav2.cts.EncoderProfileLevelTest
Change-Id: I35b7a0703333a9268dcea578328016604d7c1f54