Some device has small ROM size, so the GSI should be as small as
possible. The patch change the image sizes to be:
- 64 projects (default): 1.25GB (1280MB)
- 32 projects (default): 0.75GB (768MB)
- ARM32 projects: 734MB
Bug: 64458958
Test: Build all GSI projects
Change-Id: I7f7a266e48e99b0b4d5c6a84b8187b56e4482c94