Update installation.md (#947)
Update installation.md (#947)

Added troubleshooting step for enabling Use Host GPU checkbox in AVD settings. It appears that Google Maps requires Open GL to be enabled and working on devices for it to draw the map. See https://github.com/airbnb/react-native-maps/issues/942
zigbang/react-native-maps,hzdg/react-native-maps,amitv87/react-native-maps,jiaminglu/react-native-maps,tt-sport-mobile/react-native-maps,carleryd/react-native-maps,phantomlds/react-native-maps,athaeryn/react-native-maps,zigbang/react-native-maps,jiaminglu/react-native-maps,j0ergo/react-native-maps,tt-sport-mobile/react-native-maps,hlz2103/SwipeMe,j0ergo/react-native-maps,wannyk/react-native-maps,parkling/react-native-maps,pjamrozowicz/react-native-maps,wannyk/react-native-maps,wannyk/react-native-maps,pjamrozowicz/react-native-maps,athaeryn/react-native-maps,amitv87/react-native-maps,tt-sport-mobile/react-native-maps,pjamrozowicz/react-native-maps,jiaminglu/react-native-maps,athaeryn/react-native-maps,hlz2103/SwipeMe,hlz2103/SwipeMe,hzdg/react-native-maps,lelandrichardson/react-native-maps,zigbang/react-native-maps,j0ergo/react-native-maps,parkling/react-native-maps,hzdg/react-native-maps,phantomlds/react-native-maps,phantomlds/react-native-maps,carleryd/react-native-maps,wannyk/react-native-maps,parkling/react-native-maps,lelandrichardson/react-native-maps,lelandrichardson/react-native-maps,amitv87/react-native-maps,carleryd/react-native-maps