Rename unused args

[iBicha]

Rename unused args to silence warnings

BRIGHTSCRIPT: WARNING: unused variable 'args' in function 'processgetallcountrequest' in pkg:/components/RTA_OnDeviceComponent.brs(552)
BRIGHTSCRIPT: WARNING: unused variable 'args' in function 'processgetrootscountrequest' in pkg:/components/RTA_OnDeviceComponent.brs(556)
BRIGHTSCRIPT: WARNING: unused variable 'request' in function 'processstopresponsivenesstestingrequest' in pkg:/components/RTA_OnDeviceComponent.brs(1138)
BRIGHTSCRIPT: WARNING: unused variable 'request' in function 'processgetresponsivenesstestingdatarequest' in pkg:/components/RTA_OnDeviceComponent.brs(1180)

Tagging unused variables (Available since Roku OS 11.0) – Variables can explicitly be marked as unused by prepending an underscore to the value (for example, sub myTask(_x)). This enables avoid compilation errors to occur when an unused variable, for example, has a special behavior or another valid purpose. Unused variables generate warnings that are output to the SceneGraph debug port (8085). The maximum number of warnings that may be generated is 100.

[triwav]

Thanks @iBicha for this. I left a couple suggestions since we pass request instead of args to each function.