Prevent using android_app_import in instrumentation_for property

Previously, referencing a prebuilt android_app_import in an
android_test's instrumentation_for property instead of the source
android_app module (e.g. because the prebuilt is preferred) could
result in compilation errors if the android_test sources depended on
classes from the app. That is because while the android_app provides a
classes jar file to be added to the android_test's classpath the
android_app_import does not.

This change reports that situation as an error.

Bug: 207128192
Test: m nothing
Change-Id: I26ea90e7a3f57707fc0c094e0d8b8dc9a9e135ac
diff --git a/java/base.go b/java/base.go
index 7cd71a2..8d5fe13 100644
--- a/java/base.go
+++ b/java/base.go
@@ -1936,6 +1936,9 @@
 				sm := module.(SystemModulesProvider)
 				outputDir, outputDeps := sm.OutputDirAndDeps()
 				deps.systemModules = &systemModules{outputDir, outputDeps}
+
+			case instrumentationForTag:
+				ctx.PropertyErrorf("instrumentation_for", "dependency %q of type %q does not provide JavaInfo so is unsuitable for use with this property", ctx.OtherModuleName(module), ctx.OtherModuleType(module))
 			}
 		}