[manifest] Change the garnet import name to make jiri happy

The <import> name needs to match the corresponding <project> name in the
imported manifest. Without this, jiri seems to download garnet@master
instead of the pinned version.

Test: jiri init/import/update locally with --local-manifest
Bug: INTK-592
Change-Id: Icd0601b9958436d1af64eeb175efb88e12d25890
diff --git a/manifest/ffmpeg b/manifest/ffmpeg
index 4edcae0..adc5ae7 100644
--- a/manifest/ffmpeg
+++ b/manifest/ffmpeg
@@ -4,7 +4,7 @@
     <!-- TODO(jamesr): Remove, it should be possible to build things without garnet -->
     <import remote="https://fuchsia.googlesource.com/garnet"
             manifest="manifest/minimal"
-            name="minimal"
+            name="garnet"
             revision="8aa4ce8a3382d9e8c87016d4acb165df3f6710bd"/>
     <import remote="https://fuchsia.googlesource.com/build"
             manifest="manifest/build"