Improve app metadata, include fdroid metadata in repository

android/app/src/main/res/mipmap-hdpi/ic_launcher.png

android/app/src/main/res/mipmap-mdpi/ic_launcher.png

android/app/src/main/res/mipmap-xhdpi/ic_launcher.png

android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png

android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png

android/gradle.properties

fastlane/metadata/android/en-US/changelogs/0.txt

fastlane/metadata/android/en-US/changelogs/1.txt

fastlane/metadata/android/en-US/changelogs/10.txt

fastlane/metadata/android/en-US/changelogs/11.txt

fastlane/metadata/android/en-US/changelogs/12.txt

fastlane/metadata/android/en-US/changelogs/13.txt

fastlane/metadata/android/en-US/changelogs/14.txt

fastlane/metadata/android/en-US/changelogs/15.txt

fastlane/metadata/android/en-US/changelogs/16.txt

fastlane/metadata/android/en-US/changelogs/17.txt

fastlane/metadata/android/en-US/changelogs/18.txt

fastlane/metadata/android/en-US/changelogs/19.txt

fastlane/metadata/android/en-US/changelogs/2.txt

fastlane/metadata/android/en-US/changelogs/20.txt