Remove micro_bench.

micro_bench has been deprecated, so remove it from the list of executables
to be built by default.

Bug: 26928775

Test: Builds.
Change-Id: I701b3077ec00c7e75145aeb52463f47bf8ff2f09
diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index 12cee24..7759193 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -286,7 +286,6 @@
     adb_keys \
     iotop \
     logpersist.start \
-    micro_bench \
     perfprofd \
     procrank \
     showmap \
diff --git a/tools/warn.py b/tools/warn.py
index 4596307..33089b5 100755
--- a/tools/warn.py
+++ b/tools/warn.py
@@ -2549,7 +2549,6 @@
     simple_project_pattern('system/extras/iotop'),
     simple_project_pattern('system/extras/libfec'),
     simple_project_pattern('system/extras/memory_replay'),
-    simple_project_pattern('system/extras/micro_bench'),
     simple_project_pattern('system/extras/mmap-perf'),
     simple_project_pattern('system/extras/multinetwork'),
     simple_project_pattern('system/extras/perfprofd'),