Android gstreamer bitness

QGCCommon.pri

@@ -43,6 +43,7 @@ linux {
         DEFINES += QGC_GST_MICROHARD_ENABLED 
         QMAKE_CXXFLAGS += -Wno-address-of-packed-member
         QMAKE_CXXFLAGS += -Wno-unused-command-line-argument
+        QMAKE_CFLAGS += -Wno-unused-command-line-argument
         QMAKE_LINK += -nostdlib++ # Hack fix?: https://forum.qt.io/topic/103713/error-cannot-find-lc-qt-5-12-android
         target.path = $$DESTDIR
         equals(ANDROID_TARGET_ARCH, x86)  {

src/VideoStreaming/VideoStreaming.pri

@@ -73,11 +73,13 @@ LinuxBuild {
         QMAKE_POST_LINK += $$escape_expand(\\n) xcopy \"$$GST_ROOT_WIN\\lib\\gstreamer-1.0\\validate\\*.dll\" \"$$DESTDIR_WIN\\gstreamer-plugins\\validate\\\" /Y $$escape_expand(\\n)
     }
 } else:AndroidBuild {
-    #- gstreamer assumed to be installed in $$PWD/../../gstreamer-1.0-android-universal-1.14.4/armv7 (or x86)
-    Androidx86Build {
-        GST_ROOT = $$PWD/../../gstreamer-1.0-android-universal-1.14.4/x86
-    } else {
+    #- gstreamer assumed to be installed in $$PWD/../../gstreamer-1.0-android-universal-1.14.4/***
+    contains(QT_ARCH, arm) {
         GST_ROOT = $$PWD/../../gstreamer-1.0-android-universal-1.14.4/armv7
+    } else:contains(QT_ARCH, arm64) {
+        GST_ROOT = $$PWD/../../gstreamer-1.0-android-universal-1.14.4/arm64
+    } else {
+        GST_ROOT = $$PWD/../../gstreamer-1.0-android-universal-1.14.4/x86
     }
     exists($$GST_ROOT) {
         QMAKE_CXXFLAGS  += -pthread