Add support for mmaped file descriptor

  - create new API to create ANeuralNetworks_Memory from a mmaped fd.
  - add the corresponding Memory constructor to NeuralNetworksWrapper.h
  - Add unit test TestFd for the new API.

Bug: 63905942
Test: mm
Test: TestFd pass with CPU path.
Test: TestFd pass on sample HIDL driver, with ag/2588539

Change-Id: I1fcb0f0bd01e58bd592e18eff11c27034ee4a4c3

runtime/RequestBuilder.cpp

diff --git a/runtime/RequestBuilder.cpp b/runtime/RequestBuilder.cpp
index ab027a1..1c7e4aa 100644
--- a/runtime/RequestBuilder.cpp
+++ b/runtime/RequestBuilder.cpp
@@ -106,6 +106,9 @@
                    << count;
         return ANEURALNETWORKS_BAD_DATA;
     }
+    if (!memory->validateSize(offset, length)) {
+        return ANEURALNETWORKS_BAD_DATA;
+    }
     uint32_t poolIndex = mMemories.add(memory);
     return mInputs[index].setFromMemory(mModel->getInputOperand(index), type, poolIndex, offset,
                                         length);
@@ -129,6 +132,9 @@
                    << count;
         return ANEURALNETWORKS_BAD_DATA;
     }
+    if (!memory->validateSize(offset, length)) {
+        return ANEURALNETWORKS_BAD_DATA;
+    }
     uint32_t poolIndex = mMemories.add(memory);
     return mOutputs[index].setFromMemory(mModel->getOutputOperand(index), type, poolIndex, offset,
                                          length);