GPS: Retry inject XTRA on failure; immediately for some devices.

Some proprietary location libraries like to get interrupted while
injecting xtra data when other processes that use RPC calls are
starting during boot.

This patch retries inject_xtra_data immediately several times on
such devices (set with BOARD_USE_BROKEN_INJECT_XTRA_HACK:=true)
and retries at the normal interval on devices without that flag set.

Change-Id: I11e4b96721cc223863b17146e6b49684e27ad225