Implements Quantized LSTM op for R.

Also adds support for TENSOR_QUANT8_ASYMM_SIGNED in Test Generator.

Bug: 144841609
Bug: 145916330

Test: NeuralNetworksTest_static

Change-Id: I14b0d284b1945833d532cbaa33c66e4d77afd8b7
Merged-In: I14b0d284b1945833d532cbaa33c66e4d77afd8b7
(cherry picked from commit bac873a7b95af0338bc7da32c0fffe49bbd56181)

runtime/NeuralNetworks.cpp

diff --git a/runtime/NeuralNetworks.cpp b/runtime/NeuralNetworks.cpp
index 3542c24..5ab55db 100644
--- a/runtime/NeuralNetworks.cpp
+++ b/runtime/NeuralNetworks.cpp
@@ -188,6 +188,7 @@
               "ANEURALNETWORKS_UNIDIRECTIONAL_SEQUENCE_LSTM has changed");
 static_assert(ANEURALNETWORKS_UNIDIRECTIONAL_SEQUENCE_RNN == 93,
               "ANEURALNETWORKS_UNIDIRECTIONAL_SEQUENCE_RNN has changed");
+static_assert(ANEURALNETWORKS_QUANTIZED_LSTM == 95, "ANEURALNETWORKS_QUANTIZED_LSTM has changed");
 
 static_assert(ANEURALNETWORKS_OEM_OPERATION == 10000, "ANEURALNETWORKS_OEM_OPERATION has changed");