[Android] Text selection pane broken on Android Lollipop with RTL support enabled

Description

The "Text Selection" pane blinks and does not stay on Android Lollipop (API 21 and 22), when trying to select a text inside an Entry, and RTL support is enabled, and NavigationPage is used.

Steps to Reproduce

1. Build and launch the provided sample on a Lollipop android device or emulator (API level 21 or 22).
2. Long press on a text inside Entry.

Expected Behavior

A word inside the entry becomes selected. The "Text Selection" pane appears over the Action Bar (Toolbar) with actions copy, cut, paste etc.

Actual Behavior

Nothing in the entry becomes selected. The "Text Selection" panes appears for a moment, and then disappears. Users can't do any clipboard operations.

Basic Information

• Version with issue: XForms v3.3.0.967583, v3.4.0.1008975, v4.0.0.8055-pre1 (latest available prerelease)
• Last known good version: XForms v2.4.x (most probably, before RTL support was added)
• IDE: Microsoft Visual Studio Community 2017 (VisualStudio.15.Release/15.8.5+28010.2036)
• Platform Target Frameworks:
  • Android: Xamarin 4.11.0.776 (d15-8@1ae9b59d7), Xamarin.Android SDK 9.0.0.19 (HEAD/a8a3b0ec7), Target Framework = Android 8.1.
• Android Support Library Version: v27.0.2.1 (have not tried with other versions)
• Nuget Packages: Default from templates
• Affected Devices: Android devices and emulators running Lollipop (v5.0, v5.1, API level 21 and 22)

Screenshots

Reproduction Link

LollipopRtlTextSelection.zip