Always use perf kernel on user/userdebug builds

STS testing on Fairphone OS (gms) needs to be done on a userdebug build.
Try getting to a more robust performance with the perf kernel
config, and disabling serial logs.

Issue: FP2P-439
Change-Id: I3ac7eb3ac793e7176e449179911a73b2b96fcabd
1 file changed