Replace legacy-test with android.test.base in bp files

The legacy-test target is deprecated and will be replaced by
android.test.base. This replaces a few usages of the legacy-test target
in Android.bp files with android.test.base.

Bug: 30188076
Test: make checkbuild
Change-Id: I3575f638114fe2a3b703e67837496346bde24472
diff --git a/test-runner/Android.bp b/test-runner/Android.bp
index d495e90..dfaeed5 100644
--- a/test-runner/Android.bp
+++ b/test-runner/Android.bp
@@ -40,7 +40,7 @@
     no_framework_libs: true,
     libs: [
         "framework",
-        "legacy-test",
+        "android.test.base",
         "android.test.mock",
         "junit",
     ],