[TECHNICAL] Update min SDK - API 28 (Android 9)

[joragua]

Our criteria is setting the minimum on that level that supports at least 95%, so, under 5% could be out. That means, we are on the moment to push from 24 to 28. Under that API level, we are still supporting devices with Android 9.0 (Pie) and newer. As reference, Android 9.0 was released in August 2018.

AC:

• Upgrade min SDK to API 28 (Android 9)
• Check the code for any functionality that only applies to Android versions earlier than Android 9

TASKS

• Research (if needed)
• Create branch technical/bump_min_sdk_to_28
• Development tasks
  • Upgrade min SDK to API 28 (Android 9)
  • ...
  • Implement unit tests (if needed)
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch technical/bump_min_sdk_to_28 into master