liblog: remove stderr logger

There are no users of the liblog stderr logger, but 66 users of
android::base::StderrLogger.  We'll prefer that format and work to
merge it into liblog.

Test: liblog-unit-tests
Change-Id: Ifad24b27ac0f51379b925f6644caa1f6f3d9ad81
diff --git a/liblog/tests/Android.bp b/liblog/tests/Android.bp
index d9d1a21..45f09f2 100644
--- a/liblog/tests/Android.bp
+++ b/liblog/tests/Android.bp
@@ -54,8 +54,7 @@
     ],
     srcs: [
         "libc_test.cpp",
-        "liblog_test_default.cpp",
-        "liblog_test_stderr.cpp",
+        "liblog_test.cpp",
         "log_id_test.cpp",
         "log_radio_test.cpp",
         "log_read_test.cpp",