Implement incomplete or missing IEvsCamera methods

This CL completes IEvsCamera interface implementation by adding
following methods to a default AIDL EVS HAL implementation.
- IEvsCamera::importExternalBuffers()
- IEvsCamera::getIntParameterRange()
- IEvsCamera::setIntParameter()
- IEvsCamera::getIntParameter()

Fix: 275101894
Test: 1. Launch CVD in accelerated graphics mode (gfxstream).
      2. atest VtsHalEvsTargetTest --iteration 3
Change-Id: I70ed2a97f49d27146ce00cdaab9ca3f41a59fc98