Use toggle override if device has desktop mode...

dev option enabled.

Previous behaviour:
If a device has `enableDisplayContentModeManagement` enabled, do not use
dev options to override flag values in any cases.

New behaviour:
If a device has `enableDisplayContentModeManagement` enabled but has
`config_isDesktopModeDevOptionSupported` value set to `true`, still use
dev option to override flag values.

Bug: 434652526
Test: Manually check the feature enablement on device
Flag: EXEMPT Bug fix
Change-Id: I39e9ca4dafa9ec5958ee7ff907b70bbdcf9e76b3