Cherry-pick "action chips in share sheet" from qt-qpr1-dev.

> Action chips in share sheet.
>
> Move the Copy button to a new row of chips below the
> (now larger) preview. Optionally, if a proximity-sharing
> service is installed, show that chip as well.
>
> Bug: 143229724
> Fixes: 144290152
> Test: atest SystemUITests frameworks/base/core/tests/coretests
> Change-Id: I0d6457df85bc937f72ca97da6b4b84b634a90daf
>
> ----------
>
> Exclude nearby_sharing_component from backup test
>
> Fixes: 146019461
> Test: atest SettingsBackupTest
> Change-Id: Ieb953284f2c00d69220e776f2b628f73013140e0
>
> ----------
>
> DO NOT MERGE: Fix alignment of share chips.
>
> Bug: 144290152
> Test: visual inspection in landscape & portrait
> Change-Id: Ib60b7b56bdf23a45c61416b8309a921451010e8e
>
> ----------
>
> 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
>
> ----------
>
> DO NOT MERGE: Add another exception to the nearby-sharing chip code.
>
> Fixes: 146690046
> Test: Share from Chrome
> Change-Id: I41b3965ca2289f628a2d1de3a6da7daf01385a54

Test: atest SystemUITests frameworks/base/core/tests/coretests SettingsBackupTest
Test: manual sharing
Change-Id: Ibcf36b3c216da8e55597fbd307c9a7780cf571c6