BidiFormat adapter name for bluetooth_is_visible_message

Previously, adapter names which tend to be LTR and may appear at the
beginning of the string could cause the detected bidi direction of the whole
string (which would be RTL in RTL locales) to get miscalculated as LTR.

With this fix, not only the detected bidi direction would be correct,
but also odd adapter names would not impact the bidi layout of the
whole string.

Bug: 28816891
Change-Id: I1d25edbeeff7e9c013bb6c741e7f706431e721dc