C2SoftVpxEnc: add support for levels upto 4.1

This patch also changes 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: 151430764

Test: Uncomment the parameter for VP9 in the CTS test
Test: atest android.mediav2.cts.EncoderProfileLevelTest

Change-Id: Ie0edc2276ce123cfbcba3bf02b1aaedf5d630370