[gfx][test] Allow gfx_unittests and escher_unittests to launch subprocesses

This is required to allow a roll of googletest that enables death tests.
Without this, the death tests fail to (re-)launch themselves and so fail
unexpectedly.

INTK-682 #comment [gfx][test] Allow gfx_unittests and escher_unittests to launch subprocesses

Test: Manual with googletest roll
Change-Id: Ia392694d04ac4edafe5d54271a0c94fea251770c
diff --git a/bin/ui/meta/gfx_unittests.cmx b/bin/ui/meta/gfx_unittests.cmx
index 8fc89be..000cd29 100644
--- a/bin/ui/meta/gfx_unittests.cmx
+++ b/bin/ui/meta/gfx_unittests.cmx
@@ -14,6 +14,7 @@
             "vulkan"
         ],
         "services": [
+            "fuchsia.process.Launcher",
             "fuchsia.vulkan.loader.Loader"
         ]
     }
diff --git a/public/lib/escher/meta/escher_unittests.cmx b/public/lib/escher/meta/escher_unittests.cmx
index 7e511d2..2a58478 100644
--- a/public/lib/escher/meta/escher_unittests.cmx
+++ b/public/lib/escher/meta/escher_unittests.cmx
@@ -14,6 +14,7 @@
             "vulkan"
         ],
         "services": [
+            "fuchsia.process.Launcher",
             "fuchsia.vulkan.loader.Loader"
         ]
     }