Fix build breakage.

Change-Id: I01b00827a3099097c1181a4ae91498a6cd14c3ca
diff --git a/native/jni/src/proximity_info_state.h b/native/jni/src/proximity_info_state.h
index a986e20..53a2383 100644
--- a/native/jni/src/proximity_info_state.h
+++ b/native/jni/src/proximity_info_state.h
@@ -136,7 +136,7 @@
         return mSampledInputSize > 0;
     }
 
-    uint32_t size() const {
+    int size() const {
         return mSampledInputSize;
     }