Add Sinhala keyboard layout

java/res/xml-sw600dp/rows_sinhala.xml

java/res/xml/kbd_sinhala.xml

java/res/xml/keyboard_layout_set_sinhala.xml

java/res/xml/method.xml

java/res/xml/rowkeys_sinhala1.xml

java/res/xml/rowkeys_sinhala2.xml

java/res/xml/rowkeys_sinhala3.xml

java/res/xml/rows_sinhala.xml

...oid/inputmethod/keyboard/internal/KeyboardTextsTable.java

.../src/com/android/inputmethod/keyboard/layout/Sinhala.java

...oid/inputmethod/keyboard/layout/tests/TestsSinhalaLK.java

...board-text/res/values-si-rLK/donottranslate-more-keys.xml