Disable LTO on -eng

Speeds up incremental compile of one cpp file change
from over a minute to around 15 seconds

Bug: 111277863
Test: touch a .cpp file in hwui & mmm
Change-Id: I946ecad411a7a59f87ed9e1eeb146d6f57bd038a
diff --git a/libs/hwui/Android.bp b/libs/hwui/Android.bp
index 770a57a..c468038 100644
--- a/libs/hwui/Android.bp
+++ b/libs/hwui/Android.bp
@@ -43,6 +43,11 @@
         device_uses_hwc2: {
             cflags: ["-DUSE_HWC2"],
         },
+        eng: {
+            lto: {
+                never: true,
+            },
+        },
     },
 }