chore(android): update minSdk to API Level 23

[m1ga]

Setting minSDK to API Level 23 (was 21). API Levels overview: https://apilevels.com/

According to https://support.google.com/googleplay/answer/9037938?hl=en support for Play Services is already >= 23

Google Play services are only supported on devices with Android 6.0 (API level 23) or higher. Learn how to check and update your Android version.

And the latest Firebase FCM Module is also now 23+: https://firebase.google.com/support/release-notes/android#messaging_v25-0-0

We should follow this at some point and make the minSDK 23.

Note: the code changes are just removing if (Build.VERSION.SDK_INT >= 23) {} checks at places where we had those and they are not needed. In the Git preview it looks like a lot more changed.

People that currently have a fixed version like 22 will see:

[ERROR] The minimum supported SDK API version must be 23 or newer, but is currently set to 22

Update the android:minSdkVersion in the tiapp.xml or custom AndroidManifest to at least 23:

<ti:app xmlns:ti="http://ti.tidev.io">
    <android>
        <manifest>
            <uses-sdk android:minSdkVersion="23" />
        </manifest>
    </android>
</ti:app>

[prashantsaini1]

@m1ga There could be some apps with minSdkVersion: 21 and devices running on Android API 21 out there. This would stop running their apps on those devices. Is there any concrete reason we are removing 21 support?

[m1ga]

don't worry. doesn't have to be merged right away or even this year. But as you can see: Google is updating the Firebase modules to be minSdk 23. And it looks like androidx and latest Material are also already >=23 (https://issuetracker.google.com/issues/380448311)
So I'm sure other parts will follow soon and then it's required by the store (again: not yet). Then we have this ready and can use it.

[prashantsaini1]

@m1ga Keep it as Draft until it's mandatory and to make any further changes if required just before merge?

[m1ga]

good point, done 👍