Fix log format when masking the address to protect privacy

Without a space after the colon, when masking the address for privacy,
the colon is parsed as part of the address and cause confusion in the
log.

Example of a parsed log:
> cannot be add[MAC OUI=ed:00:0a IFACE=9]:35[PUBLIC_DEVICE_ADDRESS]

Bug: 273417286
Test: Test: m Bluetooth | ./build.py

Change-Id: I51fa65b02f2dea6da91e7aa5f62f82c783696950