KernelApiSysfsTest: remove Ipv4 test

These sysfs files are no longer required by Android.

Bug: 121379490
Test: run vts-kernel -m VtsKernelApiSysfs
Change-Id: Ic906b01330159fd24b2ae2a75532a29ee3bc77b1
diff --git a/api/sysfs/KernelApiSysfsTest.py b/api/sysfs/KernelApiSysfsTest.py
index ca5a1e3..a6b9949 100644
--- a/api/sysfs/KernelApiSysfsTest.py
+++ b/api/sysfs/KernelApiSysfsTest.py
@@ -198,16 +198,6 @@
                         except ValueError as e:
                             asserts.fail("Malformatted time_in_state file at %s" % f)
 
-    def testIpv4(self):
-        '''Check /sys/kernel/ipv4/*.'''
-        files = ['tcp_rmem_def', 'tcp_rmem_max', 'tcp_rmem_min',
-                 'tcp_wmem_def', 'tcp_wmem_max', 'tcp_wmem_min',]
-        for f in files:
-            path = '/sys/kernel/ipv4/' + f
-            self.IsReadWrite(path)
-            content = target_file_utils.ReadFileContent(path, self.shell)
-            self.ConvertToInteger(content)
-
     def testLastResumeReason(self):
         '''Check /sys/kernel/wakeup_reasons/last_resume_reason.'''
         filepath = '/sys/kernel/wakeup_reasons/last_resume_reason'