Improve class naming of group inclusion cache loaders

In [1] the inner classes were named with lowerCaseNames.
thisIsNotStandard. StandardForClassNamesBeginsWithCaps.

[1] https://gerrit-review.googlesource.com/60356

Change-Id: Ia223cb6f010555841fd00be06c56b880968312fe
(cherry picked from commit b6b88ebe9c5d85624f0fbb9dfb2c84b9373f9a4d)