[Android] fix item indices and item count in a ListView – second try

[heikow10]

Description of Change

• fix the wrong item indices and the wrong total count of items in a ListView on Android
• for this the header and footer are removed when they are empty
• partially taken from [Android] Fix for Talkback reporting incorrect number of list items (#4090) #10151
• the first try [Android] fix item indices and item count in a ListView #15306 led to a bug when using the ScrollTo method and this PR was reverted Revert "[Android] fix item indices and item count in a ListView" #15473
• in this PR the ScrollTo method was also adapted to fix this bug

Issues Resolved

• fixes [Android] Talkback reports incorrect number of list items #4090
• fixes [Bug] [Android] TalkBack always considers ListView's header and footer for indexing/counting #15305

API Changes

None

Platforms Affected

• Android

Behavioral/Visual Changes

The TalkBack screen reader now has the correct item indices and item count for the elements in a ListView.

Before/After Screenshots

Not applicable

Testing Procedure

• Android: description can be seen in Issue15305.cs

PR Checklist

• Targets the correct branch
• Tests are passing (or failures are unrelated)

[jfversluis]

Thanks so much @heikow10! I'll run this through the UI tests first now!

[jfversluis]

/azp run

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