Update view alpha to improve text color constract in Battery usage

- For light themes, first set the text color of title/summary/widget_summary to be consistent, then apply alpha = 0.65

[Before] https://screenshot.googleplex.com/4nVMMFBK7odhQju
A11y Scanner result: https://screenshot.googleplex.com/4nVMMFBK7odhQju

[After] https://screenshot.googleplex.com/B4r79v89HnWr4tw
A11y Scanner result: https://screenshot.googleplex.com/3zQfRMe4HToc8Xm

Dark mode:
[before] https://screenshot.googleplex.com/BfLxR6tqQRgP4mQ
[after]  https://screenshot.googleplex.com/8KeG62i7R5hW8Ks

Bug: 317139415
Bug: 265364351
Test: Accessibility Scanner
Change-Id: I65a71525bbce41c37ee364f3f73c0d2d1d9ace38