[test][bitmap] Relocate unit tests to exist alongside source

Change-Id: I4d26f0c5253cd7b7b52b46358936d9a37b9a0031

zircon/system/utest/bitmap/BUILD.gn → zircon/system/ulib/bitmap/test/BUILD.gn

@@ -2,6 +2,13 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+group("test") {
+  testonly = true
+  deps = [
+    ":bitmap",
+  ]
+}
+
 test("bitmap") {
   sources = [
     "raw-bitmap-tests.cpp",

zircon/system/utest/BUILD.gn

@@ -60,6 +60,7 @@ if (current_cpu != "") {
       "$zx/system/uapp/nand-util:nand-util-test",
       "$zx/system/ulib/async/test",
       "$zx/system/ulib/async-loop/test",
+      "$zx/system/ulib/bitmap/test",
       "$zx/system/ulib/blobfs/test",
       "$zx/system/ulib/bootfs:bootfs-test",
       "$zx/system/ulib/c:tests",
@@ -92,7 +93,6 @@ if (current_cpu != "") {
       "async-testutils",
       "backtrace-request",
       "biotime",
-      "bitmap",
       "blobfs",
       "blobfs-bench",
       "channel-fatal",