Camera2: Update generate scripts check for dependencies and to support MacPorts

Change-Id: Ice9b658f8e6f87a1a490c367bff2f9a685ddee44
diff --git a/camera/docs/metadata-generate b/camera/docs/metadata-generate
index bf3e3ee..a9e53d8 100755
--- a/camera/docs/metadata-generate
+++ b/camera/docs/metadata-generate
@@ -29,10 +29,11 @@
     local in=$thisdir/$1
     local out=$thisdir/$2
 
-    $thisdir/metadata_parser_xml.py $thisdir/metadata_properties.xml $in > $out
+    python $thisdir/metadata_parser_xml.py $thisdir/metadata_properties.xml $in > $out
     return $?
 }
 
+$thisdir/metadata-check-dependencies || exit 1
 $thisdir/metadata-parser-sanity-check || exit 1
 gen_file html.mako docs.html || exit 1
 gen_file camera_metadata_tag_info.mako ../src/camera_metadata_tag_info.c || exit 1