[Home screen] Enable location lock on survey activation if no LOIs

[gino-m]

i.e. if initial viewport cannot be computed.

@shobhitagarwal1612 @andreia-ferreira @hassan-nsubuga FYI

[kenstershiro]

@gino-m any steer on the priority and impact for this one?

[gino-m]

I would say "should fix" (P1) by GA release.