Utilize Java 7's diamond operator for collections

Now that Android supports Java 7 its time to start using the new
features.

This commit updates Collections to use the diamond operator (<>) and
no other features.

TODO: Add multi-catch where suitable

NOTE: try with resources is only supported in API version 19 (KitKat).
Since we target 2.3+ we can not utilize this feature

Change-Id: I76e2c31c8c151e6416a52816e211cd48c7f40523