Escaping regex reserved chars

Change-Id: Ide9addcbca07d45f3fc26b7f3ab44d165a3a5450
diff --git a/tools/package/onos-prep-karaf b/tools/package/onos-prep-karaf
index cd906dc..c707206 100755
--- a/tools/package/onos-prep-karaf
+++ b/tools/package/onos-prep-karaf
@@ -35,7 +35,7 @@
     $KARAF_DIR/etc/org.ops4j.pax.logging.cfg
 
 # Patch the fileinstall to avoid NPE when filter is null
-echo "felix.fileinstall.filter=*.jar" >> \
+echo "felix.fileinstall.filter='\\*.jar'" >> \
     $KARAF_DIR/etc/org.apache.felix.fileinstall-deploy.cfg
 
 # Patch-in proper Karaf version into the startup script