Add TENSOR_QUANT8_ASYMM_SIGNED support for activations

Ops updated: RELU, RELU1, RELU6, TANH, LOGISTIC

Fix: 143933951
Fix: 143934720
Fix: 143933831
Fix: 143934770
Fix: 143934743
Test: quantization coupling tests in CTS and VTS
Change-Id: Id5e7a8c6b30463708bd93dbf6a3f30d05c2bcf40
Merged-In: Id5e7a8c6b30463708bd93dbf6a3f30d05c2bcf40
(cherry picked from commit 3466c78b)