Revert "Revert "aconfig: @hide generated Java code""

This reverts commit c0e8ffea41306eedf099866ccd8e4c28851a0b3d.

Reason for revert: The detected build breakage was unrelated to the aconfig change. Details in b/297881670#comment11.

Change-Id: Ia32bc2e796ed3de7fa049c2c2db340f4325a2853
diff --git a/tools/aconfig/src/codegen_java.rs b/tools/aconfig/src/codegen_java.rs
index c31d715..39b286a 100644
--- a/tools/aconfig/src/codegen_java.rs
+++ b/tools/aconfig/src/codegen_java.rs
@@ -118,6 +118,7 @@
 
     const EXPECTED_FEATUREFLAGS_COMMON_CONTENT: &str = r#"
     package com.android.aconfig.test;
+    /** @hide */
     public interface FeatureFlags {
         @com.android.aconfig.annotations.AssumeFalseForR8
         boolean disabledRo();
@@ -132,6 +133,7 @@
 
     const EXPECTED_FLAG_COMMON_CONTENT: &str = r#"
     package com.android.aconfig.test;
+    /** @hide */
     public final class Flags {
         public static final String FLAG_DISABLED_RO = "com.android.aconfig.test.disabled_ro";
         public static final String FLAG_DISABLED_RW = "com.android.aconfig.test.disabled_rw";
@@ -163,6 +165,7 @@
     package com.android.aconfig.test;
     import java.util.HashMap;
     import java.util.Map;
+    /** @hide */
     public class FakeFeatureFlagsImpl implements FeatureFlags {
         public FakeFeatureFlagsImpl() {
             resetAll();
@@ -234,6 +237,7 @@
         let expect_featureflagsimpl_content = r#"
         package com.android.aconfig.test;
         import android.provider.DeviceConfig;
+        /** @hide */
         public final class FeatureFlagsImpl implements FeatureFlags {
             @Override
             public boolean disabledRo() {
@@ -316,6 +320,7 @@
         "#;
         let expect_featureflagsimpl_content = r#"
         package com.android.aconfig.test;
+        /** @hide */
         public final class FeatureFlagsImpl implements FeatureFlags {
             @Override
             public boolean disabledRo() {
diff --git a/tools/aconfig/templates/FakeFeatureFlagsImpl.java.template b/tools/aconfig/templates/FakeFeatureFlagsImpl.java.template
index 82bea81..d4283d3 100644
--- a/tools/aconfig/templates/FakeFeatureFlagsImpl.java.template
+++ b/tools/aconfig/templates/FakeFeatureFlagsImpl.java.template
@@ -3,6 +3,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
+/** @hide */
 public class FakeFeatureFlagsImpl implements FeatureFlags \{
     public FakeFeatureFlagsImpl() \{
         resetAll();
diff --git a/tools/aconfig/templates/FeatureFlags.java.template b/tools/aconfig/templates/FeatureFlags.java.template
index 31cfdfc..9350d60 100644
--- a/tools/aconfig/templates/FeatureFlags.java.template
+++ b/tools/aconfig/templates/FeatureFlags.java.template
@@ -1,5 +1,6 @@
 package {package_name};
 
+/** @hide */
 public interface FeatureFlags \{
 {{ for item in class_elements}}
 {{ -if not item.is_read_write }}
diff --git a/tools/aconfig/templates/FeatureFlagsImpl.java.template b/tools/aconfig/templates/FeatureFlagsImpl.java.template
index 96de06c..1736af9 100644
--- a/tools/aconfig/templates/FeatureFlagsImpl.java.template
+++ b/tools/aconfig/templates/FeatureFlagsImpl.java.template
@@ -3,6 +3,7 @@
 {{ if is_read_write- }}
 import android.provider.DeviceConfig;
 {{ endif }}
+/** @hide */
 public final class FeatureFlagsImpl implements FeatureFlags \{
 {{ for item in class_elements}}
     @Override
@@ -21,6 +22,7 @@
 }
 {{ else }}
 {#- Generate only stub if in test mode #}
+/** @hide */
 public final class FeatureFlagsImpl implements FeatureFlags \{
 {{ for item in class_elements}}
     @Override
diff --git a/tools/aconfig/templates/Flags.java.template b/tools/aconfig/templates/Flags.java.template
index 7f04700..95a7f3b 100644
--- a/tools/aconfig/templates/Flags.java.template
+++ b/tools/aconfig/templates/Flags.java.template
@@ -1,5 +1,6 @@
 package {package_name};
 
+/** @hide */
 public final class Flags \{
 {{- for item in class_elements}}
     public static final String FLAG_{item.flag_name_constant_suffix} = "{item.device_config_flag}";