Allow non-tool dependencies in genrules

The genrule tool dependency handling was rejecting any dependencies
that were not tools.  This caused a failure when ExtractSourceDeps
added a source file dependency on a filegroup module.  Remove the
unnecessary check in the tool handling.

Test: builds
Bug: 35002681
Change-Id: Ibd8dff306be3ef55aac2e12a28ddc187be2234d9

genrule/genrule.go

@@ -150,8 +150,6 @@ func (g *generator) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 				} else {
 					ctx.ModuleErrorf("host tool %q missing output file", ctx.OtherModuleName(module))
 				}
-			} else {
-				ctx.ModuleErrorf("unknown dependency %q", ctx.OtherModuleName(module))
 			}
 		})
 	}