feat(android): bump Kotlin version

[meidlinga]

Raises Kotlin version required in Gradle to 1.7, since sticking to a rather old version 1.5 is starting to cause problems in projects depending on this plugin.
The resulting error is: The binary version of its metadata is 1.7.1, expected version is 1.5.1.
A related topic is: https://stackoverflow.com/a/74425347/1379714

How Has This Been Tested?

Our build was broken with the above mentioned error. This change fixed it.
Other gradle/maven deps could also be updated, but introduced different requirements on the Target API.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[igorrmotta]

This fixes my problem as well. 👍

[NlL5]

Please merge this. This fixed my build process. Additionally, I tested it on Android 12 and 7.1

[andreszs]

I think this should be already merged by now, otherwise Firebase BoM will remain incompatible forever.

#218 (comment)

[willdutson]

Thanks for confirming that this change is required. Updating to 1.6.20 was sufficient for me to use @havesource/cordova-plugin-push with Android 12

[erisu]

Suggested change

	<preference name="GradlePluginKotlinVersion" value="1.7.10" />
	<preference name="GradlePluginKotlinVersion" value="1.7.21" />

Can we bump this to 1.7.21 to match with Cordova-Android 12?

Since there is other tickets to support Android 13 and it uses permissions that were added in API 33, it means this plugin will need to set the minimum requirement for cordova-android to >=12.0.0..

To match the minimum requirement.. I think it would be better to also set the default GradlePluginKotlinVersion to the same version as 12.0.0