Fix sanitizer failures that don't appear for vanilla [a|m|t]san tests.

JNI Bind is internally exercised with sanitizers, but somehow CI flagged this retroactively but not under regular testing (presumably flags differ somewhere in a CI config).

PiperOrigin-RevId: 582833429

implementation/array_view.h

@@ -26,7 +26,7 @@ namespace jni {
 
 template <typename T>
 struct ArrayViewHelper {
-  const T& val_;
+  const T val_;
   operator T() const { return val_; }
 
   ArrayViewHelper(const T& val) : val_(val) {}