[native] introduce ColorRows component

Summary: For the emoji avatar creation flow we want the same color rows logic that are found in ColorSelector. I factored out this logic into its own component so that we can better resuse it in both places

Test Plan:
There were no regressions, and ColorSelector looks and behaves as it did previously.

Reviewers: ashoat, atul

Reviewed By: ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7302