Augment HotSwitchOperation to test slow to fast case

Originally, SamplingRateHotSwitchOperation only tests the case
in which requested sensor sampling rate goes from fast to slow.
Recent regression demonstrates that it is also worthwhile to test
transition in the other direction, i.e. from slow to fast. This
CL add the slow to fast transition test.

Bug: 65138983
Test: sailfish failed the test before being patched.
Test: sailfish passed after being patched (ag/2824590)
Change-Id: If02509c75f74145544f0a2ce5d2aaec24e7326b8
Merged-In: If02509c75f74145544f0a2ce5d2aaec24e7326b8