Android, Firebase: Minsdkversion 15 Cannot Be Smaller Than Version 16

I need downgrade my minsdk for keep compatibility with some devices, so I need downgrade my version from minsdk16 -> 15. But im having this error: Manifest merger failed : uses

Solution 1:

The minimum SDK level required to use the most recently versions of Firebase libraries is 16. There is no workaround to this, other than to back up to a much older version of these libraries.

In the documentation it states:

Prerequisites

A device running:

• Android 4.1 (API level 16, Jelly Bean) or later
• Google Play services 15.0.0 or later

Solution 2:

Change the minimum SDK Level to minSdkVersion 16.

Solution 3:

With Android Studio open, in the menu select:

File>Project Structure

In the Project Structure window, select:

Modules then Default Config

In the Min SDK Version textfield type in 16 then hit OK