[Android] Color.Accent is hardcoded

[MichaelRumpler]

Description of Change

On Android Color.Accent is set to a hardcoded value in Xamarin.Forms.Forms.SetupInit (in the Platform.Android project) and it cannot be changed by the user.

This color is then used as text and separator color for TableSections. The user cannot override the color.

As the hardcoded color may not fit to the users app theme, this should be changed.

Jason Smith said on forms-devel that the code should read from the current Android theme. This change does that.

I wouldn't know how to unit test this.

Bugs Fixed

• https://bugzilla.xamarin.com/show_bug.cgi?id=42812

API Changes

None

Behavioral Changes

Color.Accent will be set to the accentColor of the current Android theme instead of the hardcoded values.

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of master at time of PR
• Changes adhere to coding standard
• Consolidate commits as makes sense

[dnfclas]

Hi @MichaelRumpler, I'm your friendly neighborhood .NET Foundation Pull Request Bot (You can call me DNFBOT). Thanks for your contribution!
You've already signed the contribution license agreement. Thanks!
We will now validate the agreement and then real humans will evaluate your PR.

TTYL, DNFBOT;