Only convert valid SharedMemInfo

This CL avoids passing nullptr to underlying HAL and cause
SEGFAULT.

Bug: 37589989
Test: compiles and VTS passing
Change-Id: Ic44409e64466e54a3a3027721897c0755ba34fc7
Merged-In: Ic44409e64466e54a3a3027721897c0755ba34fc7
diff --git a/sensors/1.0/default/convert.cpp b/sensors/1.0/default/convert.cpp
index 047374f..a5747d4 100644
--- a/sensors/1.0/default/convert.cpp
+++ b/sensors/1.0/default/convert.cpp
@@ -376,6 +376,10 @@
             return false;
     }
 
+    if (memIn.memoryHandle == nullptr) {
+        return false;
+    }
+
     memOut->size = memIn.size;
     memOut->handle = memIn.memoryHandle;
     return true;