Style cleanup for ObjPtr<>-ify changes.

Replace "ObjPtr<.> const" with "const ObjPtr<.>".

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 31113334
Change-Id: I5a1c080bc88b091e15ee9eb0bb1ef6f6f290701c
diff --git a/runtime/thread.cc b/runtime/thread.cc
index 9080418..77849a4 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -2938,13 +2938,13 @@
         soa.Decode<mirror::Object>(internal)->AsObjectArray<mirror::Object>();
     // Methods and dex PC trace is element 0.
     DCHECK(decoded_traces->Get(0)->IsIntArray() || decoded_traces->Get(0)->IsLongArray());
-    ObjPtr<mirror::PointerArray> const method_trace =
+    const ObjPtr<mirror::PointerArray> method_trace =
         ObjPtr<mirror::PointerArray>::DownCast(MakeObjPtr(decoded_traces->Get(0)));
     // Prepare parameters for StackTraceElement(String cls, String method, String file, int line)
     ArtMethod* method = method_trace->GetElementPtrSize<ArtMethod*>(i, kRuntimePointerSize);
     uint32_t dex_pc = method_trace->GetElementPtrSize<uint32_t>(
         i + method_trace->GetLength() / 2, kRuntimePointerSize);
-    ObjPtr<mirror::StackTraceElement> obj = CreateStackTraceElement(soa, method, dex_pc);
+    const ObjPtr<mirror::StackTraceElement> obj = CreateStackTraceElement(soa, method, dex_pc);
     if (obj == nullptr) {
       return nullptr;
     }