Re-enable ConstructorInitializerAllOnOneLineOrOnePerLine option.

This got lost and was untested as the same effect is achieved by
avoiding bin packing, which is active in Google style by default.
However, moving forward, we want more control over the bin packing
option(s) and thus, this flag should work as expected.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175277 91177308-0d34-0410-b5e6-96231b3b80d8