Revert "Revert "Add a way to turn off unique_fd's operator int.""

The original commit broke aosp-master-with-phones, because of
vendor libraries the depended on the int versions of libbase functions.

This patch reverts the revert, and also adds ABI-compatibility shims for
the replaced functions.

This reverts commit 2c58e1924a7bf1b44049764fddb40c1704dc288f.

Bug: http://b/131312539
Test: treehugger
Test: forrest run of aosp-master-with-phones
Change-Id: I75cc84ec8d963e20862f7662e8e2f409471f41cc
diff --git a/adb/Android.bp b/adb/Android.bp
index 87e4adc..114eb2a 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -26,6 +26,7 @@
         "-Wvla",
         "-DADB_HOST=1",         // overridden by adbd_defaults
         "-DALLOW_ADBD_ROOT=0",  // overridden by adbd_defaults
+        "-DANDROID_BASE_UNIQUE_FD_DISABLE_IMPLICIT_CONVERSION=1",
     ],
     cpp_std: "experimental",