Remove Settings.Global.TCP_DEFAULT_INIT_RWND on CS

TCP_DEFAULT_INIT_RWND setting has never been set before, CS
always read the tcp receive window size from
net.tcp.default_init_rwnd then set to net.tcp_def_init_rwnd.
Thus, remove the unnecessary setting from CS, and the property
doesn't need to set either. Because aosp/1639922 migrate the
properties, the default value has been set to kernel already.

Bug: 182538166
Test: atest FrameworksNetTests
Change-Id: I13e175ab4dea72446af7df4a25e307e5934fa813
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 92d9b08..614b7ea 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -2603,13 +2603,6 @@
         } catch (RemoteException | ServiceSpecificException e) {
             loge("Can't set TCP buffer sizes:" + e);
         }
-
-        final Integer rwndValue = Settings.Global.getInt(mContext.getContentResolver(),
-                Settings.Global.TCP_DEFAULT_INIT_RWND,
-                    mSystemProperties.getInt("net.tcp.default_init_rwnd", 0));
-        if (rwndValue != 0) {
-            mSystemProperties.setTcpInitRwnd(rwndValue);
-        }
     }
 
     @Override
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index cc58edf..fa84021 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -1513,10 +1513,7 @@
     }
 
     private ConnectivityService.Dependencies makeDependencies() {
-        doReturn(TEST_TCP_INIT_RWND).when(mSystemProperties)
-                .getInt("net.tcp.default_init_rwnd", 0);
         doReturn(false).when(mSystemProperties).getBoolean("ro.radio.noril", false);
-        doNothing().when(mSystemProperties).setTcpInitRwnd(anyInt());
         final ConnectivityService.Dependencies deps = mock(ConnectivityService.Dependencies.class);
         doReturn(mCsHandlerThread).when(deps).makeHandlerThread();
         doReturn(mNetIdManager).when(deps).makeNetIdManager();
@@ -7993,7 +7990,6 @@
 
         // Switching default network updates TCP buffer sizes.
         verifyTcpBufferSizeChange(ConnectivityService.DEFAULT_TCP_BUFFER_SIZES);
-        verify(mSystemProperties, times(1)).setTcpInitRwnd(eq(TEST_TCP_INIT_RWND));
         // Add an IPv4 address. Expect prefix discovery to be stopped. Netd doesn't tell us that
         // the NAT64 prefix was removed because one was never discovered.
         cellLp.addLinkAddress(myIpv4);
@@ -8479,14 +8475,12 @@
         mCellNetworkAgent.connect(false);
         networkCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         verifyTcpBufferSizeChange(ConnectivityService.DEFAULT_TCP_BUFFER_SIZES);
-        verify(mSystemProperties, times(1)).setTcpInitRwnd(eq(TEST_TCP_INIT_RWND));
         // Change link Properties should have updated tcp buffer size.
         LinkProperties lp = new LinkProperties();
         lp.setTcpBufferSizes(testTcpBufferSizes);
         mCellNetworkAgent.sendLinkProperties(lp);
         networkCallback.expectCallback(CallbackEntry.LINK_PROPERTIES_CHANGED, mCellNetworkAgent);
         verifyTcpBufferSizeChange(testTcpBufferSizes);
-        verify(mSystemProperties, times(2)).setTcpInitRwnd(eq(TEST_TCP_INIT_RWND));
         // Clean up.
         mCellNetworkAgent.disconnect();
         networkCallback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);