Update the slider step to 1.

Step size has to be a factor of the low/high range. 5 worked fine for
60-90 and similar, but with devices with a high refresh rate of 144 it
does not. Because we don't know what the high refresh rate might be be,
1 will work for all values.

Bug: 263296308
Test: Built the app and ran it on a physical device.
Change-Id: I2c3c10e440c7e7eca758f8ef0d50e7e0eeb958fb