Remove libimgpatch

Stop building libimgpatch as it's merely a subset of libapplypatch.

Test: unit tests pass

Change-Id: I0735ec053344404434a50e53a36e3f55964c2e4f
diff --git a/tests/Android.bp b/tests/Android.bp
index 1801f3b..a867040 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -50,12 +50,11 @@
     },
 }
 
-// libapplypatch, libapplypatch_modes, libimgpatch
+// libapplypatch, libapplypatch_modes
 libapplypatch_static_libs = [
     "libapplypatch_modes",
     "libapplypatch",
     "libedify",
-    "libimgpatch",
     "libotautil",
     "libbsdiff",
     "libbspatch",
@@ -180,7 +179,7 @@
 
     target: {
         darwin: {
-            // libimgdiff is not available on the Mac.
+            // libapplypatch in "libupdater_defaults" is not available on the Mac.
             enabled: false,
         },
     },