Fix LUTInterpolator lookup table position calc

BUG: 32830741
Test: running progress bar at 5x duration scale, no flickering
Change-Id: Ie484bdbfdf18bacc4586e36c5142e4523d08bdaa

libs/hwui/Interpolator.cpp

@@ -97,7 +97,8 @@ LUTInterpolator::~LUTInterpolator() {
 }
 
 float LUTInterpolator::interpolate(float input) {
-    float lutpos = input * mSize;
+    // lut position should only be at the end of the table when input is 1f.
+    float lutpos = input * (mSize - 1);
     if (lutpos >= (mSize - 1)) {
         return mValues[mSize - 1];
     }

tools/layoutlib/bridge/src/com/android/internal/view/animation/NativeInterpolatorFactoryHelper_Delegate.java

@@ -104,7 +104,7 @@ public class NativeInterpolatorFactoryHelper_Delegate {
 
         @Override
         public float getInterpolation(float input) {
-            float lutpos = input * mSize;
+            float lutpos = input * (mSize - 1);
             if (lutpos >= (mSize - 1)) {
                 return mValues[mSize - 1];
             }