Remove unused imports in api package

Change-Id: I7bb20d2b04a733f9ed5fa3792e6be7dbab325a59
Remove unused imports in rootwrap package

Change-Id: Ia52452f94236613f590bcd81bad51c9b007b3ff6
Remove unused imports in common package

Change-Id: I51b5ef2e7e9d1877fc2d6e439b76eae05b048436
Merge "Remove unused imports in common package"
Merge "Remove unused imports in api package"
Merge "Remove unused imports in rootwrap package"