Gradle Toolchain remove PropertyOrigin.java and other cleanups

[vmadalin]

After #28731 PR was merged a small clean up is required to remove unused variables, PropertyOrigin and also other warnings.

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[big-guy]

Thanks, I'll take a look for 8.9

[gitstream-cm]

Change Summary

This PR is 25.41% new code.

Platform	Added Lines	% of Total Line Changes	Deleted Lines	% of Total Line Changes	Files Changed	% of Total Files Changed
bt_ge_build_cache	0	0%	0	0%	0	0%
build_infrastructure	0	0%	0	0%	0	0%
core_configuration	0	0%	0	0%	0	0%
core_execution	31	25.41%	88	72.13%	12	85.71%
core_runtime	31	25.41%	88	72.13%	12	85.71%
documentation	0	0%	0	0%	0	0%
extensibility	0	0%	0	0%	0	0%
gradle_enterprise	0	0%	0	0%	0	0%
ide	0	0%	0	0%	0	0%
jvm	0	0%	0	0%	0	0%
kotlin_dsl	0	0%	0	0%	0	0%
release_coordination	0	0%	0	0%	0	0%
software	0	0%	0	0%	0	0%