Add comments for invalid IP/port and add Invalid filterID/avSyncId

To allow client to identify and specify invalid value

bug: 148110220
Test: Manual
Change-Id: Ib5e88a13cdcca0b62f55fab992293ed17e0ed708
diff --git a/tv/tuner/1.0/types.hal b/tv/tuner/1.0/types.hal
index e4874f4..dd2b48f 100644
--- a/tv/tuner/1.0/types.hal
+++ b/tv/tuner/1.0/types.hal
@@ -1924,7 +1924,7 @@
 };
 
 @export
-enum Constant : uint16_t {
+enum Constant : uint32_t {
     /**
      * An invalid packet ID in transport stream according to ISO/IEC 13818-1.
      */
@@ -1933,6 +1933,14 @@
      * An invalid Stream ID.
      */
     INVALID_STREAM_ID = 0xFFFF,
+    /**
+     * An invalid Filter ID.
+     */
+    INVALID_FILTER_ID = 0xFFFFFFFF,
+    /**
+     * An invalid AV sync hardware ID.
+     */
+    INVALID_AV_SYNC_ID = 0xFFFFFFFF,
 };
 
 /**
@@ -2151,19 +2159,37 @@
  */
 struct DemuxIpAddress {
     safe_union SrcIpAddress {
+        /**
+         * 0.0.0.0 is invalid. should be ignored.
+         */
         uint8_t[4] v4;
 
+        /**
+         * 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 is invalid. should be ignored.
+         */
         uint8_t[16] v6;
     } srcIpAddress;
 
     safe_union DstIpAddress {
+        /**
+         * 0.0.0.0 is invalid. should be ignored.
+         */
         uint8_t[4] v4;
 
+        /**
+         * 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 is invalid. should be ignored.
+         */
         uint8_t[16] v6;
     } dstIpAddress;
 
+    /**
+     * 0 is invalid. should be ignored.
+     */
     uint16_t srcPort;
 
+    /**
+     * 0 is invalid. should be ignored.
+     */
     uint16_t dstPort;
 };