[Easy Unlock] Add a convenience test target for rapid iteration.

components/proximity_auth/BUILD.gn

Index: components/proximity_auth/BUILD.gn
diff --git a/components/proximity_auth/BUILD.gn b/components/proximity_auth/BUILD.gn
index 1bd15ded02178f2c11c1d1553f9779d025ec5fb6..769341f70ea177e3d945f32703933dcf8a8cbcdc 100644
--- a/components/proximity_auth/BUILD.gn
+++ b/components/proximity_auth/BUILD.gn
@@ -38,3 +38,15 @@ source_set("unit_tests") {
     "//testing/gtest",
   ]
 }
+
+# Note: This is a convenience target for ease of rapid iteration during
+# development. It is not executed on any try or build bots.
+test("proximity_auth_unittests") {
+  sources = [
+    "run_all_unittests.cc",
+  ]
+  
+  deps = [
+    ":unit_tests",
+  ]
+}