As determined by @b8b8 , enabling NAVIC meant the more modern L5 GPS
signal was not used (L1 GPS is always available).
NAVIC, India's GNSS, probably provides the best coverage in India and
the neighbouring region. However, outside of NAVIC's coverage area, L5
GPS is highly desirable.
This patch amends the AG3335-family GPS configuration to enable L5 GPS
coverage by default. If the Lora region is set to India or Nepal,
NAVIC will be enabled instead.