[Android] The context menu is not displayed if selecting all the text from the bottom of the note

[SoftVision-CarmenFat]

[Affected Platforms]:

• Samsung J3 (Android 7.0)
• Samsung Galaxy S8 (Android 8.0.0)
• Pixel (Android 8.0.0)
• Huawei P8 Lite (Android 6.0)

[Prerequisites]:

• Have the latest version of the "Firefox Notes" application (notes-1_0-qa-v2192 custom built on 15.05.2018) installed.
• Have a note with a long text.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites.
2. Open the Notes application and log in if needed.
3. Tap the note with the long text.
4. Scroll to the bottom of the text and tap twice somewhere on the last row.
5. Tap the "Select All" option and observe the behavior.

[Expected result]:

• The entire text is selected and the context menu is displayed in a floating toast.

[Actual result]:

• The entire text is selected, but the context menu is not displayed.

[Notes]:

• This is not reproducible when selecting the text from the beginning of the note.
• Here is a screen recording of the issue: https://tinyurl.com/y7u36qp2

[vladikoff]

Pushing this out of v5