Update some Android astubx models (#1052)

Update SDKs 28-30 as our astubx format has changed. SDK 31 to come in a
follow-up PR. Also add a minimal integration test to ensure things
aren't completely broken (at least for one SDK model version, which
typically should be the latest one).

jar-infer/nullaway-integration-test/build.gradle

@@ -25,4 +25,11 @@ dependencies {
     }
     testImplementation project(":nullaway")
     testImplementation project(":jar-infer:test-java-lib-jarinfer")
+
+    // For now we can only test one of the SDK models at a time; so exactly
+    // one of the following lines should be uncommented
+    //testImplementation project(":jar-infer:android-jarinfer-models-sdk28")
+    //testImplementation project(":jar-infer:android-jarinfer-models-sdk29")
+    testImplementation project(":jar-infer:android-jarinfer-models-sdk30")
+    //testImplementation project(":jar-infer:android-jarinfer-models-sdk31")
 }

jar-infer/nullaway-integration-test/src/test/java/com/uber/nullaway/jarinfer/JarInferIntegrationTest.java

@@ -116,4 +116,37 @@ public void jarinferNullableReturnsTest() {
             "}")
         .doTest();
   }
+
+  /**
+   * Tests our pre-generated models for Android SDK classes. See also the build.gradle file for this
+   * project which determines which SDK version's models are being tested.
+   */
+  @Test
+  public void jarInferAndroidSDKModels() {
+    compilationHelper
+        .setArgs(
+            Arrays.asList(
+                "-d",
+                temporaryFolder.getRoot().getAbsolutePath(),
+                "-XepOpt:NullAway:AnnotatedPackages=com.uber",
+                "-XepOpt:NullAway:JarInferEnabled=true"))
+        // stub implementation of SpannableStringBuilder.append(CharSequence) which we know is
+        // modelled as having a @Nullable parameter
+        .addSourceLines(
+            "SpannableStringBuilder.java",
+            "package android.text;",
+            "public class SpannableStringBuilder {",
+            "  public SpannableStringBuilder append(CharSequence text) { return this; }",
+            "}")
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "class Test {",
+            "  void test1(android.text.SpannableStringBuilder builder) {",
+            "    // BUG: Diagnostic contains: passing @Nullable parameter 'null'",
+            "    builder.append(null);",
+            "  }",
+            "}")
+        .doTest();
+  }
 }