Improve main application icon

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

assets/icons/application.png

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

fastlane/metadata/android/en-US/images/icon.png

fastlane/metadata/android/fr-FR/changelogs/2.txt

icons/icon.svg