bionic tests: use GTEST_SKIP.

Also be a bit more to the point in our messages, focusing on "why" not
"what".

Test: ran tests
Change-Id: I297806c7a102bd52602dcd2fcf7a2cd34aba3a11
diff --git a/tests/getauxval_test.cpp b/tests/getauxval_test.cpp
index aa21817..f4ec7f5 100644
--- a/tests/getauxval_test.cpp
+++ b/tests/getauxval_test.cpp
@@ -61,5 +61,5 @@
     return;
   }
 #endif
-  GTEST_LOG_(INFO) << "This test is only meaningful for 32-bit ARM code on 64-bit devices.\n";
+  GTEST_SKIP() << "This test is only meaningful for 32-bit ARM code on 64-bit devices";
 }