Modify native/.flowconfig, so it includes android specific js files.

Summary: I've spotted that I had no errors in newly created file with extension .android.js There were erros obviously, but were only detected when I deleted .android from name. Those changes to .flowconfig should fix it.

Test Plan:
Tested that after changes it checks android files.
Checked ios files as well.

Reviewers: tomek, ashoat, atul, kamil

Reviewed By: ashoat

Subscribers: kamil, atul, ashoat, tomek

Differential Revision: https://phab.comm.dev/D6491