Add new `RSpec/UndescriptiveLiteralsDescription` cop #2015

Job	Run time
Confirm config and documentation	11s
Test coverage	18s
Edge RuboCop: internal_investigation	17s
Edge RuboCop: spec	25s
Ruby 2.7: internal_investigation	23s
RSpec 4	32s
Ruby 2.7: spec	30s
Ruby 3.0: internal_investigation	16s
Ruby 3.0: spec	19s
Ruby 3.1: internal_investigation	11s
Ruby 3.1: spec	22s
Ruby 3.2: internal_investigation	11s
Ruby 3.2: spec	23s
Ruby 3.3: internal_investigation	12s
Ruby 3.3: spec	22s
Ruby ruby-head: internal_investigation	13s
Ruby ruby-head: spec	21s
Ruby jruby-9.4: internal_investigation	1m 22s
Ruby jruby-9.4: spec	1m 13s
	8m 1s

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