Travis: Disable Android builds for now

As we say in French, "Trop, c'est trop !".
Those builds fail 50% of the time due to timeouts, it's pointless to have them until we
find a better solution to install the Android SDK and NDK.

Workaround for #6973.

.travis.yml

@@ -14,7 +14,7 @@ env:
   - GODOT_TARGET=iphone
   - GODOT_TARGET=osx
   - GODOT_TARGET=x11
-  - GODOT_TARGET=android
+  #- GODOT_TARGET=android
   - GODOT_TARGET=windows
 
 matrix:
@@ -69,8 +69,8 @@ addons:
 before_script:
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew update; brew install scons; fi
   - if [ "$TRAVIS_OS_NAME" = "osx" ] && [ "$GODOT_TARGET" = "android" ]; then
-      brew update; travis_wait 20 brew install -v android-sdk;
-      travis_wait 20 brew install -v android-ndk | grep -v "inflating:" | grep -v "creating:";
+      brew update; brew install -v android-sdk;
+      brew install -v android-ndk | grep -v "inflating:" | grep -v "creating:";
       export ANDROID_HOME=/usr/local/opt/android-sdk; export ANDROID_NDK_ROOT=/usr/local/opt/android-ndk;
     fi