qcacld-3.0: Modify CFG_INFRA_STA_KEEP_ALIVE_PERIOD_DEFAULT to 30
propagation from qcacld-2.0 to qcacld-3.0
Currently CFG_INFRA_STA_KEEP_ALIVE_PERIOD_DEFAULT is 0 in code
and in ini file it is 30. If this parameter is undefined in ini
file, then this KEEP alive feature gets disabled.
Change CFG_INFRA_STA_KEEP_ALIVE_PERIOD_DEFAULT value to 30
in code.
CRs-fixed: 1049206
Change-Id: Iff0933842b13482e9949473a4c8a48bf83230cc1