Add a Show my location button, and more

...ava/org/dripdronescanner/android/app/AircraftMapView.java

.../Android/app/src/main/res/drawable-hdpi/ic_center_map.png

.../Android/app/src/main/res/drawable-mdpi/ic_center_map.png

...Android/app/src/main/res/drawable-xhdpi/ic_center_map.png

...ndroid/app/src/main/res/drawable-xxhdpi/ic_center_map.png

...droid/app/src/main/res/drawable-xxxhdpi/ic_center_map.png

...-master/Android/app/src/main/res/layout/activity_main.xml

...server-master/Android/app/src/main/res/values/strings.xml