Fix calculation of concurrent_start_bytes in GrowForUtilization()

Concurrent_start_bytes currently is assigned product of bytes
allocated bytes during last GC and time spent (in seconds) in it.
Instead it should be just bytes allocated.

Bug: 71902460
Test: test-art-host
Change-Id: I6b8322756eb6464b4581311ea7e7c90ecb2cb5ae
1 file changed