hwc2: invalidate on format change

Bug: 62999638
Change-Id: I7a59c9f5a104637a7e61af04682f1239b09d4dcf
(cherry picked from commit dd6edac0dc914792547dc68b140557509b118582)
diff --git a/msm8996/sdm/libs/hwc2/hwc_layers.cpp b/msm8996/sdm/libs/hwc2/hwc_layers.cpp
index c6ae31b..5739b9d 100644
--- a/msm8996/sdm/libs/hwc2/hwc_layers.cpp
+++ b/msm8996/sdm/libs/hwc2/hwc_layers.cpp
@@ -84,7 +84,11 @@
 
   layer_buffer->width = UINT32(handle->width);
   layer_buffer->height = UINT32(handle->height);
+  auto format = layer_buffer->format;
   layer_buffer->format = GetSDMFormat(handle->format, handle->flags);
+  if (format != layer_buffer->format) {
+    needs_validate_ = true;
+  }
   if (SetMetaData(handle, layer_) != kErrorNone) {
     return HWC2::Error::BadLayer;
   }