Netd unconditionally enable bandwidth control

Remove corresponding netd command, and default enable bandwidth
controller.

Test: The bindwith control start correctly on new devices.
Change-Id: I05e1bd365af1edfade28d445cec897cc6b6b2f08
diff --git a/server/BandwidthControllerTest.cpp b/server/BandwidthControllerTest.cpp
index 90e1f3d..b5b7e7f 100644
--- a/server/BandwidthControllerTest.cpp
+++ b/server/BandwidthControllerTest.cpp
@@ -208,7 +208,7 @@
         std::string expectedAccounting =
                 useBpf ? ACCOUNT_RULES_WITH_BPF : ACCOUNT_RULES_WITHOUT_BPF;
         mBw.setBpfEnabled(useBpf);
-        mBw.enableBandwidthControl(false);
+        mBw.enableBandwidthControl();
         expectSetupCommands(expectedClean, expectedAccounting);
     }