[CEC Configuration] Introduce type checking and switch to 'int' where applicable

Bug: 168020131
Test: atest HdmiCecConfig
Change-Id: Ifdc195b8efb58b96bd6c28cc02b209813de816f4
diff --git a/data/etc/cec_config.xml b/data/etc/cec_config.xml
index 42a45e4..8e78ad7 100644
--- a/data/etc/cec_config.xml
+++ b/data/etc/cec_config.xml
@@ -1,14 +1,16 @@
 <?xml version='1.0' encoding='utf-8' standalone='yes' ?>
 <cec-settings>
   <setting name="hdmi_cec_enabled"
+           value-type="int"
            user-configurable="true">
     <allowed-values>
-      <value string-value="0" />
-      <value string-value="1" />
+      <value int-value="0" />
+      <value int-value="1" />
     </allowed-values>
-    <default-value string-value="1" />
+    <default-value int-value="1" />
   </setting>
   <setting name="send_standby_on_sleep"
+           value-type="string"
            user-configurable="true">
     <allowed-values>
       <value string-value="to_tv" />
@@ -18,6 +20,7 @@
     <default-value string-value="to_tv" />
   </setting>
   <setting name="power_state_change_on_active_source_lost"
+           value-type="string"
            user-configurable="false">
     <allowed-values>
       <value string-value="none" />
@@ -26,11 +29,12 @@
     <default-value string-value="none" />
   </setting>
   <setting name="system_audio_mode_muting"
+           value-type="int"
            user-configurable="false">
     <allowed-values>
-      <value string-value="0" />
-      <value string-value="1" />
+      <value int-value="0" />
+      <value int-value="1" />
     </allowed-values>
-    <default-value string-value="1" />
+    <default-value int-value="1" />
   </setting>
 </cec-settings>