adb: switch test_adb.py to python3.

Currently, test_adb.py doesn't work on Windows, because we're selecting
on a pipe, which doesn't work on Windows. Python 3.5 adds socketpair
support to Windows, so switch over to Python 3 to make it so we can use
that.

Test: python3 test_adb.py
Change-Id: I0fbd1bca0b28324658831d5ef8ee08aefe2b0596
diff --git a/Android.bp b/Android.bp
index dabc5ce..a18dc1a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -455,17 +455,14 @@
     srcs: [
         "test_adb.py",
     ],
-    libs: [
-        "adb_py",
-    ],
     test_config: "adb_integration_test_adb.xml",
     test_suites: ["general-tests"],
     version: {
         py2: {
-            enabled: true,
+            enabled: false,
         },
         py3: {
-            enabled: false,
+            enabled: true,
         },
     },
 }