Added GStreamer search paths for linux/arm64
PKG_GSTREAMER_PLUGIN_DIR should be checked with EXISTS, because on failure it is actually set to pkg-config error output:
Package gstreamer-1.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gstreamer-1.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gstreamer-1.0' found
Added GStreamer search paths for linux/arm64 PKG_GSTREAMER_PLUGIN_DIR should be checked with EXISTS, because on failure it is actually set to pkg-config error output: