Fix enforcement of sensor's slowest rate

This code calculates a sensor's maximum sample
period in nanoseconds. This is stored as a 64-bit
value, as required for periods greater than ~2.1
seconds.

The calculation was done with 32-bit arithmetic,
sometimes resulting in overflow. This caused the
sensor to run at its maximum rate.

(The requested period is first clipped to the maximum
period. When the maximum period appears negative, it
is always used. The now-negative period is then clipped
to the minimum period, resulting in the sensor's maximum
supported rate.)

Bug: 37465457

Test: Verified correct operation with Goldfish accelerometer,
which has a 60-second maximum period.

Change-Id: Ic75a9dc7c4e7c9ca690eafbfa51ee50540ca5aaf