Improve icons

app/src/debug/res/values/colors.xml

app/src/main/res/drawable-v26/ic_launcher_background.xml

app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

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

app/src/main/res/mipmap-hdpi/ic_launcher_foreground.png

app/src/main/res/mipmap-hdpi/ic_launcher_legacy.png

app/src/main/res/mipmap-hdpi/ic_launcher_recents.png

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

app/src/main/res/mipmap-mdpi/ic_launcher_foreground.png

app/src/main/res/mipmap-mdpi/ic_launcher_legacy.png

app/src/main/res/mipmap-mdpi/ic_launcher_recents.png

app/src/main/res/mipmap-nodpi/ic_launcher_foreground.png

app/src/main/res/mipmap-nodpi/ic_launcher_recents.png

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

app/src/main/res/mipmap-xhdpi/ic_launcher_foreground.png

app/src/main/res/mipmap-xhdpi/ic_launcher_legacy.png

app/src/main/res/mipmap-xhdpi/ic_launcher_recents.png

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

app/src/main/res/mipmap-xxhdpi/ic_launcher_foreground.png

app/src/main/res/mipmap-xxhdpi/ic_launcher_legacy.png