Put PowerState On/Off enums in quotes

Without this, the python code generator converts them to booleans and
emits True and False as the enum values in the generated code.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I4d8804e6c83055c55ebbbe032d65c6609518c711
diff --git a/yaml/xyz/openbmc_project/State/Decorator/PowerState.interface.yaml b/yaml/xyz/openbmc_project/State/Decorator/PowerState.interface.yaml
index 4f8ea2d..06aa56f 100644
--- a/yaml/xyz/openbmc_project/State/Decorator/PowerState.interface.yaml
+++ b/yaml/xyz/openbmc_project/State/Decorator/PowerState.interface.yaml
@@ -12,10 +12,10 @@
     description: >
       Power state enum.
     values:
-      - name: On
+      - name: "On"
         description: >
          The state of the object is powered on.
-      - name: Off
+      - name: "Off"
         description: >
          The state of the object is powered off.
       - name: PoweringOn