Remove non-zero amplitude validation for waveforms

The validation does not exist in Android R and is causing apps to start
crashing in S.

The validation for the static API createOneShot was maintained, as it
already existed in previous releases.

Fix: 184890231
Test: VibrationEffectTest
Change-Id: I606c943a35ddd68ccacab76f0047b9a276b5cf28

core/java/android/os/VibrationEffect.java

@@ -182,6 +182,11 @@ public abstract class VibrationEffect implements Parcelable {
      * @return The desired effect.
      */
     public static VibrationEffect createOneShot(long milliseconds, int amplitude) {
+        if (amplitude == 0) {
+            throw new IllegalArgumentException(
+                    "amplitude must either be DEFAULT_AMPLITUDE, "
+                            + "or between 1 and 255 inclusive (amplitude=" + amplitude + ")");
+        }
         return createWaveform(new long[]{milliseconds}, new int[]{amplitude}, -1 /* repeat */);
     }
 
@@ -581,22 +586,16 @@ public abstract class VibrationEffect implements Parcelable {
         public void validate() {
             int segmentCount = mSegments.size();
             boolean hasNonZeroDuration = false;
-            boolean hasNonZeroAmplitude = false;
             for (int i = 0; i < segmentCount; i++) {
                 VibrationEffectSegment segment = mSegments.get(i);
                 segment.validate();
                 // A segment with unknown duration = -1 still counts as a non-zero duration.
                 hasNonZeroDuration |= segment.getDuration() != 0;
-                hasNonZeroAmplitude |= segment.hasNonZeroAmplitude();
             }
             if (!hasNonZeroDuration) {
                 throw new IllegalArgumentException("at least one timing must be non-zero"
                         + " (segments=" + mSegments + ")");
             }
-            if (!hasNonZeroAmplitude) {
-                throw new IllegalArgumentException("at least one amplitude must be non-zero"
-                        + " (segments=" + mSegments + ")");
-            }
             if (mRepeatIndex != -1) {
                 Preconditions.checkArgumentInRange(mRepeatIndex, 0, segmentCount - 1,
                         "repeat index must be within the bounds of the segments (segments.length="

core/tests/coretests/src/android/os/VibrationEffectTest.java

@@ -102,7 +102,9 @@ public class VibrationEffectTest {
         assertThrows(IllegalArgumentException.class,
                 () -> VibrationEffect.createOneShot(1, -2).validate());
         assertThrows(IllegalArgumentException.class,
-                () -> VibrationEffect.createOneShot(1, 256).validate());
+                () -> VibrationEffect.createOneShot(1, 0).validate());
+        assertThrows(IllegalArgumentException.class,
+                () -> VibrationEffect.createOneShot(-1, 255).validate());
     }
 
     @Test
@@ -117,6 +119,7 @@ public class VibrationEffectTest {
     @Test
     public void testValidateWaveform() {
         VibrationEffect.createWaveform(TEST_TIMINGS, TEST_AMPLITUDES, -1).validate();
+        VibrationEffect.createWaveform(new long[]{10, 10}, new int[] {0, 0}, -1).validate();
         VibrationEffect.createWaveform(TEST_TIMINGS, TEST_AMPLITUDES, 0).validate();
         VibrationEffect.startWaveform()
                 .addStep(/* amplitude= */ 1, /* duration= */ 10)