Swich TEST_MAPPING config to unit_tests:true

All unit_tests:true are run in presubmit which avoids
the explicit definition of TEST_MAPPING.

Test: presubmit runs all those tests
Bug: 175408655
Change-Id: Ibfad3fe2dd8d2fa1ebc6f6bcbd8ab34c2a0069dc
diff --git a/tools/releasetools/Android.bp b/tools/releasetools/Android.bp
index cafc2bb..5cb639a 100644
--- a/tools/releasetools/Android.bp
+++ b/tools/releasetools/Android.bp
@@ -566,7 +566,9 @@
             embedded_launcher: false,
         },
     },
-    test_suites: ["general-tests"],
+    test_options: {
+        unit_test: true,
+    },
 }
 
 python_test_host {
@@ -583,5 +585,7 @@
             embedded_launcher: false,
         },
     },
-    test_suites: ["general-tests"],
+    test_options: {
+        unit_test: true,
+    },
 }