Update config to use self-contained python binaries

Build from source and remove need for virtualenv to
make it self-contained.

Test: presubmit, forrest (https://android-build.googleplex.com/builds/abtd/run/L76600000954930260)
Bug: 234458076
Ignore-AOSP-First: nearby_not_in_aosp_yet
Change-Id: Ib0afb414fdeb510577345afd650fa6f0f5b3c721
(cherry picked from commit 7599806e06)
Merged-In: Ib0afb414fdeb510577345afd650fa6f0f5b3c721

nearby/tests/multidevices/host/Android.bp

@@ -22,7 +22,10 @@ python_test_host {
     name: "NearbyMultiDevicesTestSuite",
     main: "suite_main.py",
     srcs: ["*.py"],
-    libs: ["NearbyMultiDevicesHostHelper"],
+    libs: [
+        "NearbyMultiDevicesHostHelper",
+        "mobly",
+    ],
     test_suites: [
         "general-tests",
         "mts-tethering",
@@ -38,6 +41,15 @@ python_test_host {
         // Package the JSON metadata with the Mobly test.
         "test_data/**/*",
     ],
+    version: {
+        py2: {
+            enabled: false,
+        },
+        py3: {
+            enabled: true,
+            embedded_launcher: true,
+        },
+    },
 }
 
 python_library_host {

nearby/tests/multidevices/host/AndroidTest.xml

@@ -42,11 +42,6 @@
             <option name="run-command" value="input keyevent KEYCODE_WAKEUP" />
             <option name="run-command" value="wm dismiss-keyguard" />
         </target_preparer>
-        <target_preparer class="com.android.tradefed.targetprep.PythonVirtualenvPreparer">
-          <!-- Any python dependencies can be specified and will be installed with pip -->
-          <!-- TODO(b/225958696): Import python dependencies -->
-          <option name="dep-module" value="mobly" />
-        </target_preparer>
         <target_preparer class="com.android.tradefed.targetprep.DeviceSetup">
             <option name="force-skip-system-props" value="true" /> <!-- avoid restarting device -->
             <option name="screen-always-on" value="on" />