Added launcher icon customisation

app/src/custom/res/drawable/ic_launcher_background.xml

app/src/custom/res/drawable/ic_launcher_foreground.xml

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

app/src/custom/res/mipmap-anydpi-v26/ic_launcher_round.xml

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

app/src/custom/res/mipmap-hdpi/ic_launcher_round.png

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

app/src/custom/res/mipmap-mdpi/ic_launcher_round.png

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

app/src/custom/res/mipmap-xhdpi/ic_launcher_round.png

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

app/src/custom/res/mipmap-xxhdpi/ic_launcher_round.png

app/src/custom/res/mipmap-xxxhdpi/ic_launcher.png

app/src/custom/res/mipmap-xxxhdpi/ic_launcher_round.png