Change .dbus.xml extension to .dbus-xml

Work around gyp's inability to handle compound extensions by expecting
a similar looking simple extension for XML files definine DBus
interfaces.  We'll need to rename these sources in the places we're
using them already.

Bug: 23380180
Change-Id: Ieb2050f3ef05456cd70de65c3e128d57a6a508f8
diff --git a/core/definitions.mk b/core/definitions.mk
index 36bb0d4..79831e0 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -970,7 +970,7 @@
 
 
 ######################################################################
-## Commands for generating DBus adaptors from .dbus.xml files.
+## Commands for generating DBus adaptors from .dbus-xml files.
 ######################################################################
 define generate-dbus-adaptors
 @echo "Generating DBus adaptors for $(PRIVATE_MODULE)"
@@ -982,7 +982,7 @@
 endef
 
 ######################################################################
-## Commands for generating DBus proxies from .dbus.xml files.
+## Commands for generating DBus proxies from .dbus-xml files.
 ######################################################################
 define generate-dbus-proxies
 @echo "Generating DBus proxies for $(PRIVATE_MODULE)"
@@ -990,7 +990,7 @@
 $(hide) $(DBUS_GENERATOR) \
 	--service-config=$(PRIVATE_DBUS_SERVICE_CONFIG) \
 	--proxy=$@ \
-	$(filter %.dbus.xml,$^)
+	$(filter %.dbus-xml,$^)
 endef