[Keyboard Shortcut] Update title color

Consulted with UX to update titles color to the same, in order to have
enough contrast ratio.

This change will only impact phone side's shortcut.

Bug: 323463526
Test: atest KeyboardShortcutsTest
Flag: NA
Change-Id: I008495cd068d07b57a0f2c955546a0ca6d40815c