DO NOT MERGE: Allow nearby sharing to substitute name & icon in chip

meta-data bundle keys (values are resids):

    CHIP_LABEL_METADATA_KEY = "android.service.chooser.chip_label"
    CHIP_ICON_METADATA_KEY = "android.service.chooser.chip_icon"

Test: manual, confirm that correct name & icon are used
      and that custom icon is tinted in light/dark theme
      (and that the copy chip is tinted right, too!)
Bug: 144290152
Change-Id: I57157e07630fa8bec3057e6d18336c59944fcb4f