Fix for dark cancel button on sharing sheet.

Change-Id: I5f9c1e5e2495c7d096790129925e398095ecf341
RTL styling fix for language button

* fix styles so padding/border are correct when in RTL
* check the UI language to set proper 'dir' on the button

Change-Id: If5271d59a7d9fd36fefeda904721fe509c5a8b87
Initial 'last modified' marker at bottom of page

Currently within the web view; we may move this and the language
button to native widgets attached to the end of the web view.

Change-Id: Iad197228d51ceb5e9a41ec3b588b7d37ac6b608f