Larger default buffer config in UI.
Larger default buffer config in UI.

This will make Java heap graphs recorded from the UI less likely to
overflow the buffer. Generally makes it less likely people get a partial
profile.

Change-Id: Iae5cfa77cc9280695884a9cf9adc4f0335feaab7

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto