Fix Segv on unknown address error flagged by fuzzer test.

The error is thrown when the destructor tries to free pointer memory.
This is happening for cases where the pointer was not initialized. Initializing it to a default value fixes the error.

Bug: 245135112
Test: Build mtp_host_property_fuzzer and run on the target device
(cherry picked from commit 3afa6e8)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:99d0823ca2b8275f000a437150fb8d1938b1b31a)
Merged-In: I255cd68b7641e96ac47ab81479b9b46b78c15580
Change-Id: I255cd68b7641e96ac47ab81479b9b46b78c15580

media/mtp/MtpProperty.h

@@ -26,6 +26,9 @@ namespace android {
 class MtpDataPacket;
 
 struct MtpPropertyValue {
+    // pointer str initialized to NULL so that free operation
+    // is not called for pre-assigned value
+    MtpPropertyValue() : str (NULL) {}
     union {
         int8_t          i8;
         uint8_t         u8;