libbinder: make getBlobAshmemSize private

In preparation for removing it. There are currently 3 prebuilts in the
Android source tree which reference this (from one device!).

Bug: 202029388
Test: N/A
Change-Id: Ic025418d9b4ca35cf4bfd1518de4d6db68de015d
diff --git a/libs/binder/include/binder/Parcel.h b/libs/binder/include/binder/Parcel.h
index cf30f17..32056d9 100644
--- a/libs/binder/include/binder/Parcel.h
+++ b/libs/binder/include/binder/Parcel.h
@@ -1237,7 +1237,9 @@
      */
     size_t getOpenAshmemSize() const;
 
-    // TODO(b/202029388): Remove 'getBlobAshmemSize' once ABI can be changed.
+private:
+    // TODO(b/202029388): Remove 'getBlobAshmemSize' once no prebuilts reference
+    // this
     size_t getBlobAshmemSize() const;
 };
 
diff --git a/libs/binder/tests/parcel_fuzzer/binder.cpp b/libs/binder/tests/parcel_fuzzer/binder.cpp
index 55eb847..8e8994b 100644
--- a/libs/binder/tests/parcel_fuzzer/binder.cpp
+++ b/libs/binder/tests/parcel_fuzzer/binder.cpp
@@ -284,7 +284,6 @@
         FUZZ_LOG() << "readObject: " << obj;
     },
     PARCEL_READ_NO_STATUS(uid_t, readCallingWorkSourceUid),
-    PARCEL_READ_NO_STATUS(size_t, getBlobAshmemSize),
     PARCEL_READ_NO_STATUS(size_t, getOpenAshmemSize),
 
     // additional parcelable objects defined in libbinder