qcom: Allow CAF FM radio app to read ro.vendor.fm.use_audio_session

Since commit 650a44a, com.caf.fmradio app no longer has access
to this prop.

Change-Id: Ib8828b74456ec0f92e9e36b1e5fb94ac82bbc022
diff --git a/qcom/vendor/fm_app.te b/qcom/vendor/fm_app.te
new file mode 100644
index 0000000..c37e8f5
--- /dev/null
+++ b/qcom/vendor/fm_app.te
@@ -0,0 +1 @@
+get_prop(vendor_fm_app, vendor_fm_radio_app_prop)