Set the floor value of time estimate as 2017 Jan 01 00:00:00 GMT

- The VTS test checks if the time estimate is a sane value. Thus, any
arbitrary sane value is acceptable. Here we make it consistent to
IGnssDebug.hal, where a comment mentions 2017 Jan 1 as an example of
the value.

Bug: 110094003
Test: make vts, and tested on device.
Change-Id: Ic4f6b597a718ea3e98a67c7939f9e6930d44d224