stagefright/foundation: clear type in AMessage::freeItemValue

This avoid double freeing in setItem, or if setEntry fails.

Bug: 79493409
Change-Id: Ie0d4fd7dba4d72ddc0ed00e761743caa9232582d
diff --git a/media/libstagefright/foundation/AMessage.cpp b/media/libstagefright/foundation/AMessage.cpp
index 738f066..43304aa 100644
--- a/media/libstagefright/foundation/AMessage.cpp
+++ b/media/libstagefright/foundation/AMessage.cpp
@@ -116,6 +116,7 @@
         default:
             break;
     }
+    item->mType = kTypeInt32; // clear type
 }
 
 #ifdef DUMP_STATS