Fix dispatcher crash when input monitoring enabled.
Also ensure that we actually log assertion failures.

Bug: 4203092
Change-Id: I5c14bc41b2255f876858121f5572e2de75cabcc3
diff --git a/libs/ui/Input.cpp b/libs/ui/Input.cpp
index 440ec00..bbe579e 100644
--- a/libs/ui/Input.cpp
+++ b/libs/ui/Input.cpp
@@ -724,7 +724,7 @@
             LOGD("  %d: position (%0.3f, %0.3f), vx=%0.3f, vy=%0.3f, speed=%0.3f",
                     id, positions[index].x, positions[index].y, vx, vy, sqrtf(vx * vx + vy * vy));
         } else {
-            assert(vx == 0 && vy == 0);
+            LOG_ASSERT(vx == 0 && vy == 0);
             LOGD("  %d: position (%0.3f, %0.3f), velocity not available",
                     id, positions[index].x, positions[index].y);
         }