[DocsUI M3] More dialog restyling

* Left aligned the title of the dialog.
* Update text field color in the dialog.
* Update dialog content paddings.
* For some error message dialogs, the content is rendered by the
HTML somehow, we need to programmatically set the text style and
paddings.

Check the attached bug for before/after comparison.

Bug: 404351298
Test: m DocumentsUIGoogle && manual inspection
Flag: com.android.documentsui.flags.use_material3
Change-Id: I983faa1d6df46e5b5e323278b1c7aa33fa54e895