libutils: switch Looper's fds to unique_fd.

Switch Looper to using unique_fd for its owned file descriptors, to
benefit from fdsan.

Bug: http://b/111560345
Test: treehugger
Change-Id: I8efff7741ed19fd71f82f7e604b4f1c66fc5ea2b
diff --git a/libutils/Android.bp b/libutils/Android.bp
index bbfa9d8..d635e65 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -155,6 +155,7 @@
             ],
         },
         linux: {
+            shared_libs: ["libbase"],
             srcs: [
                 "Looper.cpp",
             ],