Revert "Revert "TRDS: Darker Keyboard""

This reverts commit bd91202b3fdab6c0db88a4ab752f6d928edcb207.
Revert "Revert "LatinIME: make secondary chars better visible at TRDS dark keyboard""

This reverts commit b08955c28704d0d11c09b04757135ac3cb938d81.