drm_hwcomposer: Return an error corresponding to EX_CONFIG_FAILED for config failure

This commit adds a new ConfigError::kConfigFailed corresponding to the new
exception EX_CONFIG_FAILED.
SetConfig() should return this error if the requested config fails to be
committed.

Bug: b/391891910
Test: m drm_hwcomposer

Change-Id: Ie2ca26ff870324dc9016d32ffeb4382608f4d140
Signed-off-by: Manasi Navare <navaremanasi@google.com>
diff --git a/hwc3/Utils.h b/hwc3/Utils.h
index b322f5d..9389286 100644
--- a/hwc3/Utils.h
+++ b/hwc3/Utils.h
@@ -39,6 +39,7 @@
   kUnsupported = IComposerClient::EX_UNSUPPORTED,
   kSeamlessNotAllowed = IComposerClient::EX_SEAMLESS_NOT_ALLOWED,
   kSeamlessNotPossible = IComposerClient::EX_SEAMLESS_NOT_POSSIBLE,
+  kConfigFailed = IComposerClient::EX_CONFIG_FAILED,
 };
 }  // namespace hwc3