capture/replay: validate after resetting unpack alignment

Otherwise validation will fail, because we try to validate
the temporary set alignment against the alignment that
would be active without MEC.

Bug: angleproject:7564
Bug: angleproject:7180
Change-Id: I40cac84be122c779b9beba39f155567f9edbee75
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3936631
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Commit-Queue: Gert Wollny <gert.wollny@collabora.com>

src/libANGLE/capture/FrameCapture.cpp

@@ -5024,16 +5024,16 @@ void CaptureMidExecutionSetup(const gl::Context *context,
     // Clean up the replay state.
     replayState.reset(context);
 
-    if (validationEnabled)
-    {
-        CaptureValidateSerializedState(context, setupCalls);
-    }
-
     if (savedUnpackAlignment != currentUnpackState.alignment)
     {
         cap(CapturePixelStorei(replayState, true, GL_UNPACK_ALIGNMENT, savedUnpackAlignment));
         currentUnpackState.alignment = savedUnpackAlignment;
     }
+
+    if (validationEnabled)
+    {
+        CaptureValidateSerializedState(context, setupCalls);
+    }
 }
 
 bool SkipCall(EntryPoint entryPoint)