LG1PCloudAmbStncl: Use RangeDescriptor obj instead of StagingBuffer

We directly use an instance of RangeDescriptor to avoid incurring
the memory cost of using a StagingBuffer here. It's unnecessary
since these stencils will always be 32bits large.

stimBuffApis/livoxGen1/pcloudAmbienceStimulusBuffer.h

@@ -81,7 +81,7 @@ public:
 
 		// Construct stencils and add to list (FIFO behavior)
 		for (size_t i = 0; i < nStencils; ++i) {
-			stencils.emplace_back(nDgramsPerFrame_);
+			stencils.emplace_back();
 		}
 	}