Disable Preinstall Application , Android 4.0.3

Can disable PreInstall Application in Settings->App->App info.
But limited PreInstall.

See Source in Android-4.0.3_r1.

packages\apps\Settings\src\com\android\settings\applications
- InstalledAppDetails.java

    private void initUninstallButtons() {
        mUpdatedSysApp = (mAppEntry.info.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0;
        boolean enabled = true;
        if (mUpdatedSysApp) {
            mUninstallButton.setText(R.string.app_factory_reset);
        } else {
            if ((mAppEntry.info.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                enabled = false;
                if (SUPPORT_DISABLE_APPS) {
                    try {
                        // Try to prevent the user from bricking their phone
                        // by not allowing disabling of apps signed with the
                        // system cert and any launcher app in the system.
                        PackageInfo sys = mPm.getPackageInfo("android",
                                PackageManager.GET_SIGNATURES);
                        Intent intent = new Intent(Intent.ACTION_MAIN);
                        intent.addCategory(Intent.CATEGORY_HOME);
                        intent.setPackage(mAppEntry.info.packageName);
                        List homes = mPm.queryIntentActivities(intent, 0);
                        if ((homes != null && homes.size() > 0) ||
                                (mPackageInfo != null && mPackageInfo.signatures != null &&
                                        sys.signatures[0].equals(mPackageInfo.signatures[0]))) {
                            // Disable button for core system applications.
                            mUninstallButton.setText(R.string.disable_text);
                        } else if (mAppEntry.info.enabled) {
                            mUninstallButton.setText(R.string.disable_text);
                            enabled = true;
                        } else {
                            mUninstallButton.setText(R.string.enable_text);
                            enabled = true;
                        }
                    } catch (PackageManager.NameNotFoundException e) {
                        Log.w(TAG, "Unable to get package info", e);
                    }
                }
            } else {
                mUninstallButton.setText(R.string.uninstall_text);
            }
        }
        // If this is a device admin, it can't be uninstall or disabled.
        // We do this here so the text of the button is still set correctly.
        if (mDpm.packageHasActiveAdmins(mPackageInfo.packageName)) {
            enabled = false;
        }
        mUninstallButton.setEnabled(enabled);
        if (enabled) {
            // Register listener
            mUninstallButton.setOnClickListener(this);
        }
    }

The following System applications can not be disabled.
- Update from Market.
- Application has Activity with Intent.CATEGORY_HOME.(= Launcher Application)
- Application has same signature of System. ( = System Application)



If you set to disable, Application Icon in App List do not show.