UPDATE (26th September 2016):
I just checked the fix in play-services-maps 9.6.1
compile 'com.google.android.gms:play-services-maps:9.6.1'
The issue 10201 is closed and release notes here
I think its a render time log. No connection with java code. I also have same log. and i feel its cause by : SupportMapFragment in xml file. When i touch Map, GL render layout and prints this log.
It is inside Map Library. So we can't modify it. but i think sometimes it cause memory overload. and so system calls GC to dump memory.
It's just a warning. So ignore it for now. but it should be fix by Google map library maker.
Edition (1st August, 2016) : now its a known issue and will be solve in next Google Play Library release. ref
Edition (2nd August, 2016) : got an update to play-services-maps as 9.2.1 -> 9.4.0, but warning message still there.
Edition (5th August, 2016) : the fix is not in 9.4 but will be in an upcoming release ref
Note : for hide bunch of same messages i found one trick here.