Fix bpp mismatch

Bug: 26980851

GL_RGBA16F was being incorrectly calculated
as 4 bpp instead of 16 in Texture's objectSize(),
leading to a mismatch in cache size tracking
in GradientCache

Change-Id: I533c52fcdf9910d7a7d14bbd80965b8cbef8e147
diff --git a/libs/hwui/GradientCache.cpp b/libs/hwui/GradientCache.cpp
index 11293d6..88ae02b 100644
--- a/libs/hwui/GradientCache.cpp
+++ b/libs/hwui/GradientCache.cpp
@@ -165,6 +165,10 @@
     generateTexture(colors, positions, info.width, 2, texture);
 
     mSize += size;
+    LOG_ALWAYS_FATAL_IF((int)size != texture->objectSize(),
+            "size != texture->objectSize(), size %" PRIu32 ", objectSize %" PRIu32
+            " width = %" PRIu32 " bytesPerPixel() = %" PRIu32,
+            size, texture->objectSize(), info.width, bytesPerPixel());
     mCache.put(gradient, texture);
 
     return texture;