Fix name for ContextMenu.SelectedOption.SelectedText in histograms.xml
Fix name for ContextMenu.SelectedOption.SelectedText in histograms.xml

Samples are being recorded into "ContextMenu.SelectedOption.SelectedText" in the code, but histograms.xml used to define a histogram called "ContextMenu.SelectedOption.TextSelection".

BUG=None

Review URL: https://codereview.chromium.org/1390123003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#352978}

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