fix: In HFP change roam indicator from CALL to ROAM

[Dowafu]

Fix in HandsFreeProfile (HFP):
The AgIndicator is erroneously set to CALL for the roam function. This small patch sets it to ROAM instead.

[google-cla]

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[zxzxwu]

Please sign the CLA, thank you

[Dowafu]

Please excuse the delay, I forgot to trigger the rescan. Now the CLA should be resolved.