Disable Google Earth

Adding Issue #1157 to put back

QGCExternalLibs.pri

@@ -166,14 +166,15 @@ OSGDependency {
 # [OPTIONAL] Google Earth dependency. Provides Google Earth view to supplement 2D map view.
 # Only supported on Mac and Windows where Google Earth can be installed.
 #
-contains(DEFINES, DISABLE_GOOGLE_EARTH) {
+GoogleEarthDisableOverride {
+    contains(DEFINES, DISABLE_GOOGLE_EARTH) {
         message("Skipping support for Google Earth view (manual override from command line)")
         DEFINES -= DISABLE_GOOGLE_EARTH
-}
+    }
-# Otherwise the user can still disable this feature in the user_config.pri file.
+    # Otherwise the user can still disable this feature in the user_config.pri file.
-else:exists(user_config.pri):infile(user_config.pri, DEFINES, DISABLE_GOOGLE_EARTH) {
+    else:exists(user_config.pri):infile(user_config.pri, DEFINES, DISABLE_GOOGLE_EARTH) {
         message("Skipping support for Google Earth view (manual override from user_config.pri)")
-} else:MacBuild {
+    } else:MacBuild {
         message("Including support for Google Earth view")
         DEFINES += QGC_GOOGLE_EARTH_ENABLED
         HEADERS += src/ui/map3D/QGCGoogleEarthView.h \
@@ -183,7 +184,7 @@ else:exists(user_config.pri):infile(user_config.pri, DEFINES, DISABLE_GOOGLE_EAR
                     src/ui/map3D/QGCWebPage.cc \
                     src/ui/QGCWebView.cc
         FORMS += src/ui/QGCWebView.ui
-} else:WindowsBuild {
+    } else:WindowsBuild {
             message("Including support for Google Earth view")
             DEFINES += QGC_GOOGLE_EARTH_ENABLED
             HEADERS += src/ui/map3D/QGCGoogleEarthView.h \
@@ -194,8 +195,11 @@ else:exists(user_config.pri):infile(user_config.pri, DEFINES, DISABLE_GOOGLE_EAR
                         src/ui/QGCWebView.cc
             FORMS += src/ui/QGCWebView.ui
             QT += axcontainer
-} else {
+    } else {
         message("Skipping support for Google Earth view (unsupported platform)")
+    }
+} else {
+    message("Skipping support for Google Earth due to Issue 1157")
 }
 
 #