Add IGsiService::suggestScratchSize() am: 721a0e4b06 am: 0958afc108

Original change: https://android-review.googlesource.com/c/platform/system/gsid/+/1536726

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I0df1b06ecd0944f76e894864fada03461c9a6e9c