Fix --no-gles config, and ease the pain of standalone emulator build

1. Apparently, emulator build fails when configured with --no-gles option due to
   missing android_setPostCallback implementation.
2. It's painful to configure standalone emulator build WITH OpenGLES, since it requires
   explicit using of --gles-include, and --gles-lib when launching android-configure.sh
   To ease that pain, just use default location for standalone emulator build.

Change-Id: I2d9ed56d68a4ab1cb1ec294817f22dca80d33223
diff --git a/android-configure.sh b/android-configure.sh
index 01fc2c4..9510ece 100755
--- a/android-configure.sh
+++ b/android-configure.sh
@@ -255,6 +255,32 @@
             fi
         fi
     fi
+else
+    if [ "$GLES_PROBE" = "yes" ]; then
+        GLES_SUPPORT=yes
+        if [ -z "$GLES_INCLUDE" ]; then
+            log "GLES       : Probing for headers"
+            GLES_INCLUDE=../../sdk/emulator/opengl/host/include
+            if [ -d "$GLES_INCLUDE" ]; then
+                log "GLES       : Headers in $GLES_INCLUDE"
+            else
+                echo "Warning: Could not find OpenGLES emulation include dir: $GLES_INCLUDE"
+                echo "Disabling GLES emulation from this build!"
+                GLES_SUPPORT=no
+            fi
+        fi
+        if [ -z "$GLES_LIBS" ]; then
+            log "GLES       : Probing for host libraries"
+            GLES_LIBS=../../out/host/$OS/lib
+            if [ -d "$GLES_LIBS" ]; then
+                echo "GLES       : Libs in $GLES_LIBS"
+            else
+                echo "Warning: Could nof find OpenGLES emulation libraries in: $GLES_LIBS"
+                echo "Disabling GLES emulation from this build!"
+                GLES_SUPPORT=no
+            fi
+        fi
+    fi
 fi  # IN_ANDROID_BUILD = no
 
 if [ "$GLES_SUPPORT" = "yes" ]; then
diff --git a/android/opengles.c b/android/opengles.c
index b265428..f56252c 100644
--- a/android/opengles.c
+++ b/android/opengles.c
@@ -283,6 +283,11 @@
     return -1;
 }
 
+void
+android_setPostCallback(OnPostFunc onPost, void* onPostContext)
+{
+}
+
 void android_getOpenglesHardwareStrings(char* vendor, size_t vendorBufSize,
                                        char* renderer, size_t rendererBufSize,
                                        char* version, size_t versionBufSize)