Fix building on JitPack

They doesn't have latest CMake installed by default.
But to install it, we need to use sdkmanager which
doesn't support Java 11. So we must first use Java 8,
download cmake, then install and use Java 11.

Alternatively we can forget about installing newer CMake
as compilation works also with older version, but there
are warnings that NDK needs newer CMake. And we would also
have to remove the required CMake version from build.gradle.

Also we must ignore :sample project when building on JitPack
as it breaks build too.

jitpack.yml

@@ -1,2 +1,8 @@
+# NOTE: sdkmanager doesn't support Java 11, so we must run it with Java 8, and enable Java 11 afterwards
 jdk:
-  - openjdk11
+  - openjdk8
+#  - openjdk11
+before_install:
+  - yes | sdkmanager "cmake;3.22.1"
+  - sdk install java 11.0.2-open
+  - sdk use java 11.0.2-open

settings.gradle

@@ -1,2 +1,4 @@
 include ':tesseract4android'
-include ':sample'
+if (!System.env.JITPACK) {
+    include ':sample'
+}