ozone: Only reset HDR if it was previously set

With the current implementation, we check if the property
HDR_OUTPUT_METADATA exists and if it does, then we always set its value.
This is wasteful because most likely the HDR metadata property is not
already configured.

Optimize that by adding a condition: if the property is empty and was
never configured, then return. Otherwise, reset the connector property.
This saves a full modeset during boot.

Bug: b:326980151, b:339498874, b:378982496, b:386722343, b:388332124
Change-Id: Ia95b8f6991c54650afc2c5011d4f14c8986f6e96
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6170633
Reviewed-by: Gil Dekel <gildekel@chromium.org>
Commit-Queue: Paz Zcharya <pazz@google.com>
Reviewed-by: Sasha McIntosh <sashamcintosh@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1405699}