liblog#__android_log_btwrite__android_logger_list_read fail

With replaced AOSP system.img, adb can be root by other test.
The fail is caused by the reason that logdw is still active after
__android_log_close().

This test has a potential bug.
proc/net/unix may contain '\0', then "grep" command will treat this file
as a bianry file.
Using "grep -a" instead of "grep" could be a safer way to get the right
results from bianry file.

bug: 112250722
Test: Build CTS
Test: Pixel 2 XL PPP5.180610.010 passed the following tests
Test: run cts-on-gsi -m CtsLiblogTestCases --skip-preconditions
Change-Id: I9bfca1522e90ebb68e6cecbdb63e3b67248e47c4
Signed-off-by: Xinghua Yang <xinghua.yang@mediatek.com>
diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index a8a9a12..a20808e 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -130,7 +130,7 @@
 
 static bool isLogdwActive() {
   std::string logdwSignature =
-      popenToString("grep /dev/socket/logdw /proc/net/unix");
+      popenToString("grep -a /dev/socket/logdw /proc/net/unix");
   size_t beginning = logdwSignature.find(' ');
   if (beginning == std::string::npos) return true;
   beginning = logdwSignature.find(' ', beginning + 1);
@@ -144,7 +144,7 @@
   end = logdwSignature.find(' ', end + 1);
   if (end == std::string::npos) return true;
   std::string allLogdwEndpoints = popenToString(
-      "grep ' 00000002" + logdwSignature.substr(beginning, end - beginning) +
+      "grep -a ' 00000002" + logdwSignature.substr(beginning, end - beginning) +
       " ' /proc/net/unix | " +
       "sed -n 's/.* \\([0-9][0-9]*\\)$/ -> socket:[\\1]/p'");
   if (allLogdwEndpoints.length() == 0) return true;