Revert "Add Foldable feature flag"

This reverts commit 821f43aa64.

Reason for revert: better fit:
- restrict the Package Manager feature flags to features for which the app developer would need to "target"
- typically hardware types should be mutually exclusive to each other

Bug: 124406307
Test: make checkbuild
Change-Id: Ie247a21eb8bbc83efad833ca8db675fd11e7ea4e

api/current.txt

@@ -11647,7 +11647,6 @@ package android.content.pm {
     field public static final String FEATURE_FAKETOUCH_MULTITOUCH_DISTINCT = "android.hardware.faketouch.multitouch.distinct";
     field public static final String FEATURE_FAKETOUCH_MULTITOUCH_JAZZHAND = "android.hardware.faketouch.multitouch.jazzhand";
     field public static final String FEATURE_FINGERPRINT = "android.hardware.fingerprint";
-    field public static final String FEATURE_FOLDABLE = "android.hardware.type.foldable";
     field public static final String FEATURE_FREEFORM_WINDOW_MANAGEMENT = "android.software.freeform_window_management";
     field public static final String FEATURE_GAMEPAD = "android.hardware.gamepad";
     field public static final String FEATURE_HIFI_SENSORS = "android.hardware.sensor.hifi_sensors";

core/java/android/content/pm/PackageManager.java

@@ -2563,14 +2563,6 @@ public abstract class PackageManager {
     @SdkConstant(SdkConstantType.FEATURE)
     public static final String FEATURE_PC = "android.hardware.type.pc";
 
-    /**
-     * Feature for {@link #getSystemAvailableFeatures} and
-     * {@link #hasSystemFeature}: This is a foldable device. Properties such as
-     * the display size may change in response to being folded.
-     */
-    @SdkConstant(SdkConstantType.FEATURE)
-    public static final String FEATURE_FOLDABLE = "android.hardware.type.foldable";
-
     /**
      * Feature for {@link #getSystemAvailableFeatures} and {@link #hasSystemFeature}:
      * The device supports printing.